# CVE-2026-97929: ALSA: usbusx2y: validate URB actual_length in interrupt callback

> A malicious USB device can trigger uninitialized memory disclosure in the ALSA usbusx2y driver, allowing local attackers to read kernel heap data.

- **Severity:** Not scored
- **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:** 25 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-104387, BELL-CVE-2026-97929, DEBIAN-CVE-2026-97929, GHSA-7jc2-x3x6-f88w, UBUNTU-CVE-2026-97929

## What is CVE-2026-97929?

CVE-2026-97929 is a vulnerability in Linux, published on 25 Sep 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: usbusx2y: validate URB actual_length in interrupt callback

i_usx2y_in04_int() processes the interrupt URB data without checking
urb->actual_length.  A short transfer from a malfunctioning device
would cause the handler to process uninitialized heap data from the
kmalloc-allocated in04_buf, which is then copied to the mmap-accessible
ctl_snapshot[] array.

Fix by using kzalloc() for in04_buf to zero-initialize the buffer,
and adding an actual_length check to skip processing on short
transfers while still resubmitting the URB.

## Which versions are affected by CVE-2026-97929?


## How do I fix CVE-2026-97929?

Apply the vendor's patch.

## Is CVE-2026-97929 being exploited?

There is no known exploitation of CVE-2026-97929 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97929 and fix it if it is affected.

What it is: CVE-2026-97929 is a vulnerability in Linux, published on 25 Sep 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-2026-97929 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-2026-97929/ (Markdown: https://insights.sbomify.com/CVE-2026-97929/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97929
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97929
- OSV: https://osv.dev/vulnerability/CVE-2026-97929

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97929/
Summaries are generated and may contain mistakes; the official description above is the record.