CVE-2026-25068
📋 TL;DR
This CVE describes a heap-based buffer overflow vulnerability in alsa-lib's topology mixer control decoder. Attackers can exploit this by providing a malicious .tplg file with an excessive num_channels value, causing out-of-bounds heap writes that may lead to crashes or potentially arbitrary code execution. Systems using affected alsa-lib versions (1.2.2 through 1.2.15.2) that process untrusted topology files are vulnerable.
💻 Affected Systems
- alsa-lib
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Arbitrary code execution with the privileges of the process parsing the .tplg file, potentially leading to full system compromise if the process runs with elevated privileges.
Likely Case
Application crash (denial of service) when processing malicious .tplg files, potentially affecting audio functionality on the system.
If Mitigated
No impact if systems don't process untrusted .tplg files or have updated alsa-lib.
🎯 Exploit Status
Exploitation requires the victim to process a malicious .tplg file. No authentication needed if user can supply such files.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: alsa-lib after commit 5f7fe33002d2d98d84f72e381ec2cccc0d5d3d40
Vendor Advisory: https://github.com/alsa-project/alsa-lib/commit/5f7fe33002d2d98d84f72e381ec2cccc0d5d3d40
Restart Required: Yes
Instructions:
1. Update alsa-lib to version after commit 5f7fe33. 2. For Linux distributions, use package manager: 'sudo apt update && sudo apt upgrade alsa-lib' (Debian/Ubuntu) or 'sudo yum update alsa-lib' (RHEL/CentOS). 3. Restart affected audio services or reboot system.
🔧 Temporary Workarounds
Restrict .tplg file processing
linuxPrevent processing of untrusted .tplg files by restricting file permissions or using application sandboxing.
chmod 600 /usr/share/alsa/topology/*.tplg
chown root:root /usr/share/alsa/topology/*.tplg
🧯 If You Can't Patch
- Implement strict file validation for .tplg files before processing
- Use SELinux/AppArmor to restrict alsa-lib's file access capabilities
🔍 How to Verify
Check if Vulnerable:
Check alsa-lib version: 'dpkg -l | grep alsa-lib' or 'rpm -qa | grep alsa-lib'. If version is between 1.2.2 and 1.2.15.2, system is vulnerable.Check Version:
dpkg -l | grep alsa-lib # Debian/Ubuntu
rpm -qa | grep alsa-lib # RHEL/CentOS
pkg info alsa-lib # FreeBSDVerify Fix Applied:
Verify alsa-lib version is newer than 1.2.15.2 or includes commit 5f7fe33: 'git log --oneline | grep 5f7fe33' in alsa-lib source directory.📡 Detection & Monitoring
Log Indicators:
- Segmentation fault or crash logs from audio-related processes
- Unexpected termination of alsa-lib dependent applications
Network Indicators:
- None - this is a local file parsing vulnerability
SIEM Query:
process.name: ("pulseaudio", "alsactl") AND event.action: ("segmentation fault", "crash")