From 3dbf115e0b4c33c0e9d1d173c0f4db773ee28609 Mon Sep 17 00:00:00 2001
From: "CanbiZ (MickLesk)" <47820557+MickLesk@users.noreply.github.com>
Date: Fri, 20 Mar 2026 13:18:01 +0100
Subject: [PATCH] VM's: add input validation and hostname sanitization to all
 VM scripts (#12973)

* Sanitize hostname generation from VM_NAME

Replace the previous simple space-removal with stricter sanitization when deriving the hostname from VM_NAME. Non-alphanumeric/hyphen sequences are collapsed to a single hyphen and leading/trailing hyphens are trimmed, preserving lowercase and ensuring a cleaner, more valid hostname string.

* fix(vm): validate CORE_COUNT input - require positive integer, re-ask on invalid

* Validate RAM input in VM scripts

Add input validation and retry loop for RAM size prompts across multiple VM scripts. Each modified advanced_settings() now wraps the whiptail RAM input in a while-true loop, ensures a default of 2048 when empty, validates that the value is a positive integer, shows an "INVALID INPUT" msgbox on bad values, and calls exit-script when the dialog is canceled. Also fixes quoting of RAM_SIZE in several scripts. Affected files: vm/archlinux-vm.sh, vm/debian-13-vm.sh, vm/mikrotik-routeros.sh, vm/nextcloud-vm.sh, vm/owncloud-vm.sh, vm/ubuntu2204-vm.sh, vm/ubuntu2404-vm.sh, vm/ubuntu2504-vm.sh, vm/umbrel-os-vm.sh. These changes prevent invalid RAM entries and improve user experience when configuring VMs.

* Validate RAM input for VM scripts

Add robust RAM input validation to multiple VM helper scripts (debian, docker, haos, openwrt, opnsense, pimox-haos, truenas). Each RAM prompt is now wrapped in a while loop that: provides a sensible default when the input is empty, ensures the value is a positive integer via regex, shows an "INVALID INPUT" whiptail message on bad input, and exits cleanly when the user cancels. Also fixed quoting of variable tests and normalized echoing of the allocated RAM. The pimox change preserves exit-status handling while integrating the same validation loop.

* fix(vm): validate VLAN input - require 1-4094 range, re-ask on invalid

* fix(vm): validate MTU input - require 576-65520 range, re-ask on invalid

* fix(vm): validate MAC address input - require XX:XX:XX:XX:XX:XX format, re-ask on invalid
---
 vm/archlinux-vm.sh      | 117 ++++++++++++++++++++++++----------------
 vm/debian-13-vm.sh      | 117 ++++++++++++++++++++++++----------------
 vm/debian-vm.sh         | 117 ++++++++++++++++++++++++----------------
 vm/docker-vm.sh         | 114 +++++++++++++++++++++++++--------------
 vm/haos-vm.sh           | 117 ++++++++++++++++++++++++----------------
 vm/mikrotik-routeros.sh | 117 ++++++++++++++++++++++++----------------
 vm/nextcloud-vm.sh      | 117 ++++++++++++++++++++++++----------------
 vm/openwrt-vm.sh        | 116 ++++++++++++++++++++++++---------------
 vm/opnsense-vm.sh       |  41 ++++++++------
 vm/owncloud-vm.sh       | 117 ++++++++++++++++++++++++----------------
 vm/pimox-haos-vm.sh     | 104 +++++++++++++++++++++--------------
 vm/truenas-vm.sh        | 117 ++++++++++++++++++++++++----------------
 vm/ubuntu2204-vm.sh     | 117 ++++++++++++++++++++++++----------------
 vm/ubuntu2404-vm.sh     | 117 ++++++++++++++++++++++++----------------
 vm/ubuntu2504-vm.sh     | 117 ++++++++++++++++++++++++----------------
 vm/umbrel-os-vm.sh      | 117 ++++++++++++++++++++++++----------------
 16 files changed, 1090 insertions(+), 689 deletions(-)

diff --git a/vm/archlinux-vm.sh b/vm/archlinux-vm.sh
index 482f09c85..e1ff0eb28 100644
--- a/vm/archlinux-vm.sh
+++ b/vm/archlinux-vm.sh
@@ -310,7 +310,10 @@ function advanced_settings() {
       HN="arch-linux"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo "${VM_NAME,,}" | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -332,27 +335,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$CORE_COUNT" ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$RAM_SIZE" ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z "$BRG" ]; then
@@ -365,43 +372,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$MAC1" ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$VLAN1" ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$MTU1" ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/debian-13-vm.sh b/vm/debian-13-vm.sh
index 4b52b7d47..2f3522f16 100644
--- a/vm/debian-13-vm.sh
+++ b/vm/debian-13-vm.sh
@@ -325,7 +325,10 @@ function advanced_settings() {
       HN="debian"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo "${VM_NAME,,}" | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -347,27 +350,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$CORE_COUNT" ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$RAM_SIZE" ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z "$BRG" ]; then
@@ -380,43 +387,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$MAC1" ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$VLAN1" ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$MTU1" ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   select_cloud_init
 
diff --git a/vm/debian-vm.sh b/vm/debian-vm.sh
index cff40a43a..b7193f04f 100644
--- a/vm/debian-vm.sh
+++ b/vm/debian-vm.sh
@@ -315,7 +315,10 @@ function advanced_settings() {
       HN="debian"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -337,27 +340,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -370,43 +377,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "CLOUD-INIT" --yesno "Configure the VM with Cloud-init?" --defaultno 10 58); then
     echo -e "${CLOUD}${BOLD}${DGN}Configure Cloud-init: ${BGN}yes${CL}"
diff --git a/vm/docker-vm.sh b/vm/docker-vm.sh
index 42fb22091..194470a40 100644
--- a/vm/docker-vm.sh
+++ b/vm/docker-vm.sh
@@ -251,7 +251,10 @@ function advanced_settings() {
     if [ -z $VM_NAME ]; then
       HN="docker"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
     fi
     echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
   else
@@ -275,24 +278,32 @@ function advanced_settings() {
   fi
 
   # CPU Cores
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
+    else
+      exit_script
     fi
-    echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
-  else
-    exit_script
-  fi
+  done
 
   # RAM Size
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 4096 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="4096"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 4096 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="4096"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 4096)." 8 58
+    else
+      exit_script
     fi
-    echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
-  else
-    exit_script
-  fi
+  done
 
   # Bridge
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
@@ -305,42 +316,63 @@ function advanced_settings() {
   fi
 
   # MAC Address
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
+      exit_script
     fi
-    echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
-  else
-    exit_script
-  fi
+  done
 
   # VLAN
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan (leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan (leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
+      exit_script
     fi
-    echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
-  else
-    exit_script
-  fi
+  done
 
   # MTU
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
+      exit_script
     fi
-    echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
-  else
-    exit_script
-  fi
+  done
 
   # Start VM
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
diff --git a/vm/haos-vm.sh b/vm/haos-vm.sh
index 832640e0a..af0b0af80 100644
--- a/vm/haos-vm.sh
+++ b/vm/haos-vm.sh
@@ -391,7 +391,10 @@ function advanced_settings() {
       HN="haos${BRANCH}"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -416,27 +419,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="4096"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="4096"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 4096)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -449,43 +456,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/mikrotik-routeros.sh b/vm/mikrotik-routeros.sh
index 4e46f5900..b2ee376cc 100644
--- a/vm/mikrotik-routeros.sh
+++ b/vm/mikrotik-routeros.sh
@@ -377,7 +377,10 @@ function advanced_settings() {
       HN="mikrotik-routeros-chr"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -399,27 +402,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -432,43 +439,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/nextcloud-vm.sh b/vm/nextcloud-vm.sh
index 3307cc6b7..6f14cdbcc 100644
--- a/vm/nextcloud-vm.sh
+++ b/vm/nextcloud-vm.sh
@@ -313,7 +313,10 @@ function advanced_settings() {
       HN="nextcloud-vm"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -335,27 +338,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -368,43 +375,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/openwrt-vm.sh b/vm/openwrt-vm.sh
index c7e030245..2ad7de968 100644
--- a/vm/openwrt-vm.sh
+++ b/vm/openwrt-vm.sh
@@ -328,30 +328,41 @@ function advanced_settings() {
     if [ -z $VM_NAME ]; then
       HN="openwrt"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
     fi
     echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
   else
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 1 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="1"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 1 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="1"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${DGN}Allocated Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 1)." 8 58
+    else
+      exit-script
     fi
-    echo -e "${DGN}Allocated Cores: ${BGN}$CORE_COUNT${CL}"
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 256 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="256"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 256 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="256"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${DGN}Allocated RAM: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 256)." 8 58
+    else
+      exit-script
     fi
-    echo -e "${DGN}Allocated RAM: ${BGN}$RAM_SIZE${CL}"
-  else
-    exit-script
-  fi
+  done
 
   if DISK_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" \
     --inputbox "Set Disk Size in GiB (e.g., 1, 2, 4)" 8 58 "1" \
@@ -422,41 +433,62 @@ function advanced_settings() {
     exit-script
   fi
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a WAN Vlan (leave blank for default)" 8 58 --title "WAN VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a WAN Vlan (leave blank for default)" 8 58 --title "WAN VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${DGN}Using WAN Vlan: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${DGN}Using WAN Vlan: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
+      exit-script
     fi
-    echo -e "${DGN}Using WAN Vlan: ${BGN}$VLAN1${CL}"
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN2=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a LAN Vlan" 8 58 999 --title "LAN VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN2 ]; then
-      VLAN2="Default"
-      LAN_VLAN=""
+  while true; do
+    if VLAN2=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a LAN Vlan" 8 58 999 --title "LAN VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN2" ]; then
+        VLAN2="Default"
+        LAN_VLAN=""
+        echo -e "${DGN}Using LAN Vlan: ${BGN}$VLAN2${CL}"
+        break
+      fi
+      if [[ "$VLAN2" =~ ^[0-9]+$ ]] && [ "$VLAN2" -ge 1 ] && [ "$VLAN2" -le 4094 ]; then
+        LAN_VLAN=",tag=$VLAN2"
+        echo -e "${DGN}Using LAN Vlan: ${BGN}$VLAN2${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      LAN_VLAN=",tag=$VLAN2"
+      exit-script
     fi
-    echo -e "${DGN}Using LAN Vlan: ${BGN}$VLAN2${CL}"
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DGN}Using Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DGN}Using Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
+      exit-script
     fi
-    echo -e "${DGN}Using Interface MTU Size: ${BGN}$MTU1${CL}"
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     START_VM="yes"
diff --git a/vm/opnsense-vm.sh b/vm/opnsense-vm.sh
index 71ec65f41..13f964588 100644
--- a/vm/opnsense-vm.sh
+++ b/vm/opnsense-vm.sh
@@ -421,30 +421,41 @@ function advanced_settings() {
     if [ -z "$VM_NAME" ]; then
       HN="OPNsense"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
     fi
     echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
   else
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 4 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$CORE_COUNT" ]; then
-      CORE_COUNT="2"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 4 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="4"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${DGN}Allocated Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 4)." 8 58
+    else
+      exit-script
     fi
-    echo -e "${DGN}Allocated Cores: ${BGN}$CORE_COUNT${CL}"
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 8192 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="8192"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 8192 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="8192"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${DGN}Allocated RAM: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 8192)." 8 58
+    else
+      exit-script
     fi
-    echo -e "${DGN}Allocated RAM: ${BGN}$RAM_SIZE${CL}"
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a LAN Bridge" 8 58 vmbr0 --title "LAN BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
diff --git a/vm/owncloud-vm.sh b/vm/owncloud-vm.sh
index d0ebe2115..742bebc79 100644
--- a/vm/owncloud-vm.sh
+++ b/vm/owncloud-vm.sh
@@ -314,7 +314,10 @@ function advanced_settings() {
       HN="owncloud-vm"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -336,27 +339,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -369,43 +376,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/pimox-haos-vm.sh b/vm/pimox-haos-vm.sh
index a3bbba24d..71981cfb2 100644
--- a/vm/pimox-haos-vm.sh
+++ b/vm/pimox-haos-vm.sh
@@ -274,26 +274,35 @@ function advanced_settings() {
     echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
   else
     if [ $exitstatus = 0 ]; then
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
     fi
   fi
-  CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
-  exitstatus=$?
-  if [ -z $CORE_COUNT ]; then
-    CORE_COUNT="2"
-    echo -e "${DGN}Allocated Cores: ${BGN}$CORE_COUNT${CL}"
-  else
-    if [ $exitstatus = 0 ]; then echo -e "${DGN}Allocated Cores: ${BGN}$CORE_COUNT${CL}"; fi
-  fi
-  RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 4096 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
-  exitstatus=$?
-  if [ -z $RAM_SIZE ]; then
-    RAM_SIZE="4096"
-    echo -e "${DGN}Allocated RAM: ${BGN}$RAM_SIZE${CL}"
-  else
-    if [ $exitstatus = 0 ]; then echo -e "${DGN}Allocated RAM: ${BGN}$RAM_SIZE${CL}"; fi
-  fi
+  while true; do
+    CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
+    exitstatus=$?
+    if [ $exitstatus -ne 0 ]; then exit-script; fi
+    if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+    if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+      echo -e "${DGN}Allocated Cores: ${BGN}$CORE_COUNT${CL}"
+      break
+    fi
+    whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
+  done
+  while true; do
+    RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 4096 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
+    exitstatus=$?
+    if [ $exitstatus -ne 0 ]; then exit-script; fi
+    if [ -z "$RAM_SIZE" ]; then RAM_SIZE="4096"; fi
+    if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+      echo -e "${DGN}Allocated RAM: ${BGN}$RAM_SIZE${CL}"
+      break
+    fi
+    whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 4096)." 8 58
+  done
   BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
   exitstatus=$?
   if [ -z $BRG ]; then
@@ -302,39 +311,56 @@ function advanced_settings() {
   else
     if [ $exitstatus = 0 ]; then echo -e "${DGN}Using Bridge: ${BGN}$BRG${CL}"; fi
   fi
-  MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
-  exitstatus=$?
-  if [ -z $MAC1 ]; then
-    MAC="$GEN_MAC"
-    echo -e "${DGN}Using MAC Address: ${BGN}$MAC${CL}"
-  else
-    if [ $exitstatus = 0 ]; then
+  while true; do
+    MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
+    exitstatus=$?
+    if [ $exitstatus -ne 0 ]; then exit-script; fi
+    if [ -z "$MAC1" ]; then
+      MAC="$GEN_MAC"
+      echo -e "${DGN}Using MAC Address: ${BGN}$MAC${CL}"
+      break
+    fi
+    if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
       MAC="$MAC1"
       echo -e "${DGN}Using MAC Address: ${BGN}$MAC1${CL}"
+      break
     fi
-  fi
-  VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
-  exitstatus=$?
-  if [ $exitstatus = 0 ]; then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default" VLAN=""
+    whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
+  done
+  while true; do
+    VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
+    exitstatus=$?
+    if [ $exitstatus -ne 0 ]; then exit-script; fi
+    if [ -z "$VLAN1" ]; then
+      VLAN1="Default"
+      VLAN=""
       echo -e "${DGN}Using Vlan: ${BGN}$VLAN1${CL}"
-    else
+      break
+    fi
+    if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
       VLAN=",tag=$VLAN1"
       echo -e "${DGN}Using Vlan: ${BGN}$VLAN1${CL}"
+      break
     fi
-  fi
-  MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
-  exitstatus=$?
-  if [ $exitstatus = 0 ]; then
-    if [ -z $MTU1 ]; then
-      MTU1="Default" MTU=""
+    whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
+  done
+  while true; do
+    MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
+    exitstatus=$?
+    if [ $exitstatus -ne 0 ]; then exit-script; fi
+    if [ -z "$MTU1" ]; then
+      MTU1="Default"
+      MTU=""
       echo -e "${DGN}Using Interface MTU Size: ${BGN}$MTU1${CL}"
-    else
+      break
+    fi
+    if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
       MTU=",mtu=$MTU1"
       echo -e "${DGN}Using Interface MTU Size: ${BGN}$MTU1${CL}"
+      break
     fi
-  fi
+    whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
+  done
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${DGN}Start VM when completed: ${BGN}yes${CL}"
     START_VM="yes"
diff --git a/vm/truenas-vm.sh b/vm/truenas-vm.sh
index 3e7274543..a4447b898 100644
--- a/vm/truenas-vm.sh
+++ b/vm/truenas-vm.sh
@@ -355,7 +355,10 @@ function advanced_settings() {
     if [ -z $VM_NAME ]; then
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -380,27 +383,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 "$CORE_COUNT" --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 "$CORE_COUNT" --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 "$RAM_SIZE" --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="8192"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 "$RAM_SIZE" --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="8192"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 8192)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 "$BRG" --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -413,43 +420,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --defaultno --title "IMPORT ONBOARD DISKS" --yesno "Would you like to import onboard disks?" 10 58); then
     echo -e "${DISK}${BOLD}${DGN}Import onboard disks: ${BGN}yes${CL}"
diff --git a/vm/ubuntu2204-vm.sh b/vm/ubuntu2204-vm.sh
index 0c281ec7f..b6e637804 100644
--- a/vm/ubuntu2204-vm.sh
+++ b/vm/ubuntu2204-vm.sh
@@ -310,7 +310,10 @@ function advanced_settings() {
       HN="ubuntu"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -332,27 +335,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -365,43 +372,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/ubuntu2404-vm.sh b/vm/ubuntu2404-vm.sh
index eba9846a5..911644550 100644
--- a/vm/ubuntu2404-vm.sh
+++ b/vm/ubuntu2404-vm.sh
@@ -313,7 +313,10 @@ function advanced_settings() {
       HN="ubuntu"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -335,27 +338,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -368,43 +375,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/ubuntu2504-vm.sh b/vm/ubuntu2504-vm.sh
index f9040855d..e448a1e0f 100644
--- a/vm/ubuntu2504-vm.sh
+++ b/vm/ubuntu2504-vm.sh
@@ -312,7 +312,10 @@ function advanced_settings() {
       HN="ubuntu"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -334,27 +337,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -367,43 +374,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"
diff --git a/vm/umbrel-os-vm.sh b/vm/umbrel-os-vm.sh
index fc193d0bb..dc4cb13fb 100644
--- a/vm/umbrel-os-vm.sh
+++ b/vm/umbrel-os-vm.sh
@@ -373,7 +373,10 @@ function advanced_settings() {
       HN="umbrelos"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
@@ -398,27 +401,31 @@ function advanced_settings() {
     exit-script
   fi
 
-  if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $CORE_COUNT ]; then
-      CORE_COUNT="2"
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+  while true; do
+    if CORE_COUNT=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate CPU Cores" 8 58 2 --title "CORE COUNT" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$CORE_COUNT" ]; then CORE_COUNT="2"; fi
+      if [[ "$CORE_COUNT" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "CPU Cores must be a positive integer (e.g., 2)." 8 58
     else
-      echo -e "${CPUCORE}${BOLD}${DGN}CPU Cores: ${BGN}$CORE_COUNT${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $RAM_SIZE ]; then
-      RAM_SIZE="2048"
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+  while true; do
+    if RAM_SIZE=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Allocate RAM in MiB" 8 58 2048 --title "RAM" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$RAM_SIZE" ]; then RAM_SIZE="2048"; fi
+      if [[ "$RAM_SIZE" =~ ^[1-9][0-9]*$ ]]; then
+        echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "RAM Size must be a positive integer in MiB (e.g., 2048)." 8 58
     else
-      echo -e "${RAMSIZE}${BOLD}${DGN}RAM Size: ${BGN}$RAM_SIZE${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if BRG=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Bridge" 8 58 vmbr0 --title "BRIDGE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
     if [ -z $BRG ]; then
@@ -431,43 +438,61 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $VLAN1 ]; then
-      VLAN1="Default"
-      VLAN=""
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+  while true; do
+    if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$VLAN1" ]; then
+        VLAN1="Default"
+        VLAN=""
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      if [[ "$VLAN1" =~ ^[0-9]+$ ]] && [ "$VLAN1" -ge 1 ] && [ "$VLAN1" -le 4094 ]; then
+        VLAN=",tag=$VLAN1"
+        echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "VLAN must be a number between 1 and 4094, or leave blank for default." 8 58
     else
-      VLAN=",tag=$VLAN1"
-      echo -e "${VLANTAG}${BOLD}${DGN}VLAN: ${BGN}$VLAN1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
-  if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MTU1 ]; then
-      MTU1="Default"
-      MTU=""
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+  while true; do
+    if MTU1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set Interface MTU Size (leave blank for default)" 8 58 --title "MTU SIZE" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MTU1" ]; then
+        MTU1="Default"
+        MTU=""
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      if [[ "$MTU1" =~ ^[0-9]+$ ]] && [ "$MTU1" -ge 576 ] && [ "$MTU1" -le 65520 ]; then
+        MTU=",mtu=$MTU1"
+        echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "MTU Size must be a number between 576 and 65520, or leave blank for default." 8 58
     else
-      MTU=",mtu=$MTU1"
-      echo -e "${DEFAULT}${BOLD}${DGN}Interface MTU Size: ${BGN}$MTU1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   if (whiptail --backtitle "Proxmox VE Helper Scripts" --title "START VIRTUAL MACHINE" --yesno "Start VM when completed?" 10 58); then
     echo -e "${GATEWAY}${BOLD}${DGN}Start VM when completed: ${BGN}yes${CL}"