CVE-2026-23191 – A race condition vulnerability in the Linux ker... (How to Fix)

Q: What is the severity of CVE-2026-23191?

CVE-2026-23191 has a CVSS score of N/A (Unknown). A race condition vulnerability in the Linux kernel's ALSA loopback driver allows use-after-free (UAF) when programs frequently trigger PCM operations while opening/closing tied streams. This could lead to kernel crashes or potential privilege escalation. Affects Linux systems using the ALSA loopback audio driver.

📋 TL;DR

A race condition vulnerability in the Linux kernel's ALSA loopback driver allows use-after-free (UAF) when programs frequently trigger PCM operations while opening/closing tied streams. This could lead to kernel crashes or potential privilege escalation. Affects Linux systems using the ALSA loopback audio driver.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not specified in CVE, but patches exist in stable kernel trees

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with ALSA loopback driver (snd-aloop) loaded or in use. Many servers may not have this module loaded by default.

⚠️ 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.

Recommended Actions:

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

Kernel panic leading to system crash or potential privilege escalation to root if an attacker can exploit the UAF to execute arbitrary code in kernel context.

🟠

Likely Case

System instability, kernel crashes, or denial of service affecting audio functionality and potentially other system operations.

🟢

If Mitigated

Minimal impact if the system doesn't use ALSA loopback driver or has proper isolation preventing user access to vulnerable interfaces.

🌐 Internet-Facing: LOW - This is a local kernel vulnerability requiring access to the audio subsystem, not directly exploitable over network.

🏢 Internal Only: MEDIUM - Requires local user access or ability to run programs that trigger the vulnerable audio operations.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger specific audio operations. Race conditions are timing-sensitive and may be difficult to reliably exploit.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patched in stable kernel versions via commits: 5727ccf9d19ca414cb76d9b647883822e2789c2e, 826af7fa62e347464b1b4e0ba2fe19a92438084f, bad15420050db1803767e58756114800cce91ea4

Vendor Advisory: https://git.kernel.org/stable/c/5727ccf9d19ca414cb76d9b647883822e2789c2e

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify snd-aloop module is updated.

🔧 Temporary Workarounds

Disable ALSA loopback module

Linux

Prevent loading of vulnerable snd-aloop kernel module

echo 'blacklist snd-aloop' >> /etc/modprobe.d/blacklist-aloop.conf
rmmod snd-aloop 2>/dev/null || true

🧯 If You Can't Patch

Restrict user access to audio devices and prevent untrusted users from running audio applications
Monitor system for kernel panics or unusual audio subsystem behavior

🔍 How to Verify

Check if Vulnerable:

Check if snd-aloop module is loaded: lsmod | grep snd_aloop. If loaded, check kernel version against patched versions.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes patch commits or is newer than patched versions. Check dmesg for no new crashes related to ALSA.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in dmesg or /var/log/kern.log
ALSA driver error messages
Use-after-free kernel warnings

Network Indicators:

None - local vulnerability only

SIEM Query:

source="kernel" AND ("panic" OR "UAF" OR "use-after-free" OR "ALSA" OR "snd-aloop")

📊 Metadata

CVE ID: CVE-2026-23191

CVSS v3 Score: N/A (Unknown)

Published: February 14, 2026

Last Updated: February 18, 2026

🔗 References

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