Linux Exit Code 126 - Command Not Executable

What It Means

Exit code 126 indicates that the command was found on the system but could not be executed. This is almost always a permissions issue — the file exists but lacks the execute permission bit, or the file format is not recognized as an executable.

Common Causes

• Script file missing the execute permission (chmod +x)
• Binary file with wrong permissions
• Trying to execute a non-executable file (e.g., a text file)
• Wrong file format for the system architecture (e.g., ARM binary on x86)
• Missing or incorrect shebang line (#!/bin/bash)
• File system mounted with noexec option
• SELinux or AppArmor denying execution

How to Fix

Add execute permissions

# Check current permissions
ls -la script.sh
# -rw-r--r-- 1 user user 1234 Jan 1 12:00 script.sh  (no 'x' flag)

# Add execute permission
chmod +x script.sh

# Or set specific permissions
chmod 755 script.sh  # rwxr-xr-x

# Now it can be run
./script.sh
echo $?  # 0 (success)

Add a proper shebang line

# Script must start with a shebang line
#!/bin/bash
echo "Hello, World!"

# For Python scripts
#!/usr/bin/env python3
print("Hello, World!")

# For Node.js scripts
#!/usr/bin/env node
console.log("Hello, World!");

Run with an interpreter explicitly

# Instead of executing directly, call the interpreter
bash script.sh
python3 script.py
node script.js

Check for noexec mount

# Check if the filesystem is mounted with noexec
mount | grep noexec

# If /tmp is noexec, copy to a different location
cp /tmp/script.sh ~/script.sh
chmod +x ~/script.sh
~/script.sh

# Or remount without noexec (requires root)
sudo mount -o remount,exec /tmp

Check file format

# Verify the file type
file ./mybinary
# Should show: ELF 64-bit LSB executable, x86-64...
# Not: ASCII text, or ELF 32-bit (on a 64-bit system)

# Check for Windows line endings (can cause issues with shebang)
file script.sh
# If it shows "with CRLF line terminators":
dos2unix script.sh

Related Errors

• Linux Exit Code 127 - Command not found: The command does not exist at all.
• Linux Exit Code 1 - General error: The command ran but failed.
• Linux Exit Code 2 - Misuse: Incorrect command syntax or arguments.