CVE-2026-22184
📋 TL;DR
This CVE describes a global buffer overflow vulnerability in zlib's untgz utility when processing excessively long archive names via command line. The vulnerability allows arbitrary code execution but only affects the standalone demonstration utility, not the core zlib compression library. Systems that have the untgz utility installed and execute it with untrusted input are affected.
💻 Affected Systems
- zlib
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the user running untgz, potentially leading to full system compromise if executed with elevated privileges.
Likely Case
Local privilege escalation or denial of service when untrusted users can supply archive names to untgz commands.
If Mitigated
Limited impact if untgz is not installed or not executed with untrusted input, as the vulnerability requires user interaction.
🎯 Exploit Status
Exploitation requires user interaction to execute untgz with malicious input. Public proof-of-concept exists in disclosure references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: zlib 1.3.1.3 and later
Vendor Advisory: https://github.com/madler/zlib/issues/1142
Restart Required: No
Instructions:
1. Update zlib to version 1.3.1.3 or later. 2. For source installations: download latest version from zlib.net and recompile. 3. For package managers: use system update commands (apt update && apt upgrade zlib, yum update zlib, etc.).
🔧 Temporary Workarounds
Remove untgz utility
allRemove or disable the vulnerable untgz binary since it's a demonstration utility not required for core functionality.
rm /usr/bin/untgz
rm /usr/local/bin/untgz
Restrict untgz execution
allRemove execute permissions or restrict access to untgz utility.
chmod -x /usr/bin/untgz
chmod 000 /usr/bin/untgz
🧯 If You Can't Patch
- Remove or disable the untgz utility entirely
- Implement strict input validation and avoid passing untrusted archive names to untgz
🔍 How to Verify
Check if Vulnerable:
Check if untgz exists and zlib version is <=1.3.1.2: which untgz && zlib-flate --versionCheck Version:
zlib-flate --version 2>/dev/null || echo 'zlib-flate not found'Verify Fix Applied:
Verify zlib version is >=1.3.1.3: zlib-flate --version | grep -q '1.3.1.[3-9]\|1.3.[2-9]\|1.[4-9]'📡 Detection & Monitoring
Log Indicators:
- Execution of untgz with unusually long command-line arguments
- Process crashes of untgz with segmentation faults
Network Indicators:
- No network indicators as this is a local utility
SIEM Query:
process.name:"untgz" AND (cmdline.length > 256 OR exit_code:139)