CVE-2026-23191: Linux kernel · ALSA: aloop: Fix racy access at PCM trigger
Affects Linux kernelSource CVE Database V5
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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
- git.kernel.org/stable/c/f57467114f40c5aacebbea96fb4ff9e5cd2b7f18 (opens in a new tab)
- git.kernel.org/stable/c/c99be0d5af02adebe9cb6f9869d20397fa9935a3 (opens in a new tab)
- git.kernel.org/stable/c/f3ce8be893726899e3053cf8059ecc95d8410359 (opens in a new tab)
- git.kernel.org/stable/c/0e6245b2424d126ac90018142d09f0707e12998b (opens in a new tab)
- git.kernel.org/stable/c/bad15420050db1803767e58756114800cce91ea4 (opens in a new tab)
- git.kernel.org/stable/c/5727ccf9d19ca414cb76d9b647883822e2789c2e (opens in a new tab)
- git.kernel.org/stable/c/826af7fa62e347464b1b4e0ba2fe19a92438084f (opens in a new tab)