# CVE-2026-74497: ALSA: usb-audio: Clamp frame size in implicit-feedback mode

> A malicious USB device can cause a denial of service in the Linux kernel by sending oversized sync packets that exceed hardware frame limits.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-96488, BELL-CVE-2026-74497, DEBIAN-CVE-2026-74497, GHSA-56rg-f4qq-ghhv, UBUNTU-CVE-2026-74497

## What is CVE-2026-74497?

CVE-2026-74497 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ALSA: usb-audio: Clamp frame size in implicit-feedback mode

snd_usb_handle_sync_urb() scales received sync packet sizes by the sender's
stride and stores the result directly in out_packet->packet_size[i]. If a
connected USB device sends an oversized sync packet, this frame count can
exceed ep->maxframesize.

The un-clamped frame count then propagates to the playback endpoint queue,
potentially driving packet transfers beyond the endpoint's hardware frame
limits.

Cap the calculated frame count against ep->maxframesize in
snd_usb_handle_sync_urb() to prevent oversized packets from entering the
playback queue.

## Which versions are affected by CVE-2026-74497?


## How do I fix CVE-2026-74497?

Apply the vendor's patch.

## Is CVE-2026-74497 being exploited?

There is no known exploitation of CVE-2026-74497 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74497 and fix it if it is affected.

What it is: CVE-2026-74497 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74497 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74497/ (Markdown: https://insights.sbomify.com/CVE-2026-74497/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74497
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74497
- OSV: https://osv.dev/vulnerability/CVE-2026-74497

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74497/
Summaries are generated and may contain mistakes; the official description above is the record.