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VulnerabilityPublished Updated

CVE-2026-23191: Linux kernel · ALSA: aloop: Fix racy access at PCM trigger

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in f57467114f40c5aacebbea96fb4ff9e5cd2b7f18 : patch Linux kernel soon.

Data as of 26 Oct 2026, 09:29 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-06-16.

Patch
Available – fixed in f57467114f40c5aacebbea96fb4ff9e5cd2b7f18, f3ce8be893726899e3053cf8059ecc95d8410359, c99be0d5af02adebe9cb6f9869d20397fa9935a3 +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 14 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ b1c73fc8e697eb73e23603e465e9af2711ed4183, < f57467114f40c5aacebbea96fb4ff9e5cd2b7f18
Fixed in
  • f57467114f40c5aacebbea96fb4ff9e5cd2b7f18
LinuxLinuxAffected
  • ≥ b1c73fc8e697eb73e23603e465e9af2711ed4183, < f3ce8be893726899e3053cf8059ecc95d8410359
Fixed in
  • f3ce8be893726899e3053cf8059ecc95d8410359
LinuxLinuxAffected
  • ≥ b1c73fc8e697eb73e23603e465e9af2711ed4183, < c99be0d5af02adebe9cb6f9869d20397fa9935a3
Fixed in
  • c99be0d5af02adebe9cb6f9869d20397fa9935a3
LinuxLinuxAffected
  • ≥ b1c73fc8e697eb73e23603e465e9af2711ed4183, < bad15420050db1803767e58756114800cce91ea4
Fixed in
  • bad15420050db1803767e58756114800cce91ea4
LinuxLinuxAffected
  • ≥ b1c73fc8e697eb73e23603e465e9af2711ed4183, < 5727ccf9d19ca414cb76d9b647883822e2789c2e
Fixed in
  • 5727ccf9d19ca414cb76d9b647883822e2789c2e
LinuxLinuxAffected
  • ≥ b1c73fc8e697eb73e23603e465e9af2711ed4183, < 826af7fa62e347464b1b4e0ba2fe19a92438084f
Fixed in
  • 826af7fa62e347464b1b4e0ba2fe19a92438084f

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: aloop: Fix racy access at PCM trigger The PCM trigger callback of aloop driver tries to check the PCM state and stop the stream of the tied substream in the corresponding cable. Since both check and stop operations are performed outside the cable lock, this may result in UAF when a program attempts to trigger frequently while opening/closing the tied stream, as spotted by fuzzers. For addressing the UAF, this patch changes two things: - It covers the most of code in loopback_check_format() with cable->lock spinlock, and add the proper NULL checks. This avoids already some racy accesses. - In addition, now we try to check the state of the capture PCM stream that may be stopped in this function, which was the major pain point leading to UAF.

References

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