# CVE-2026-89954: mtd: afs: validate v2 image info bounds

> An attacker with flash access can trigger an integer overflow in the AFS v2 parser, potentially causing a kernel crash or arbitrary code execution.

- **Severity:** High 8.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101358, BELL-CVE-2026-89954, DEBIAN-CVE-2026-89954, GHSA-jx3v-9v24-f367, UBUNTU-CVE-2026-89954

## What is CVE-2026-89954?

CVE-2026-89954 is a high-severity 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:

mtd: afs: validate v2 image info bounds

The AFS v2 parser uses footer[8] to locate the image information block
inside the current erase block, then uses the image information
region_count to walk entries from a fixed local array. The footer offset
and region count come from flash contents and are not checked against the
erase block or the local image-info array before use.

Reject v2 entries whose image information offset would underflow the
erase block calculation, and reject region counts that cannot fit in the
local image-info array before walking region entries.

## Which versions are affected by CVE-2026-89954?


## How do I fix CVE-2026-89954?

Apply the vendor's patch.

## Is CVE-2026-89954 being exploited?

There is no known exploitation of CVE-2026-89954 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89954 and fix it if it is affected.

What it is: CVE-2026-89954 is a high-severity 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-2026-89954 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-2026-89954/ (Markdown: https://insights.sbomify.com/CVE-2026-89954/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89954
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89954
- OSV: https://osv.dev/vulnerability/CVE-2026-89954

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89954/
Summaries are generated and may contain mistakes; the official description above is the record.