# CVE-2026-89879: media: s2255: bound JPEG frame size before copying into the buffer

> A malicious USB device can trigger a buffer overflow in the s2255 kernel driver, potentially leading to code execution or system crash.

- **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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101298, BELL-CVE-2026-89879, DEBIAN-CVE-2026-89879, GHSA-w8vh-2wxg-frpg, UBUNTU-CVE-2026-89879

## What is CVE-2026-89879?

CVE-2026-89879 is a memory corruption vulnerability in Linux, published on 16 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:

media: s2255: bound JPEG frame size before copying into the buffer

s2255_fillbuff() memcpy()s vc->jpg_size bytes of a captured JPEG/MJPEG
frame into the vb2 plane.  vc->jpg_size is taken verbatim from the
S2255_MARKER_FRAME header the device sends (pdword[4] in save_frame())
and, unlike the frame payload length just above it, is never bounded:

	payload = le32_to_cpu(pdword[3]);
	if (payload > vc->req_image_size)	/* payload is checked ... */
		return -EINVAL;
	vc->pkt_size = payload;
	vc->jpg_size = le32_to_cpu(pdword[4]);	/* ... jpg_size is not */

A malicious or malfunctioning device can therefore report a jpg_size
larger than the destination vb2 plane, and the memcpy() writes past it.
jpg_size is a signed int, so a value with the top bit set also turns
into a huge length.

Reject a frame whose jpg_size is negative or exceeds the plane size
before copying it.

## Which versions are affected by CVE-2026-89879?


## How do I fix CVE-2026-89879?

Apply the vendor's patch.

## Is CVE-2026-89879 being exploited?

There is no known exploitation of CVE-2026-89879 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89879 and fix it if it is affected.

What it is: CVE-2026-89879 is a memory corruption vulnerability in Linux, published on 16 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-2026-89879 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-2026-89879/ (Markdown: https://insights.sbomify.com/CVE-2026-89879/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89879
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89879
- OSV: https://osv.dev/vulnerability/CVE-2026-89879

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89879/
Summaries are generated and may contain mistakes; the official description above is the record.