# CVE-2026-80657: accel/amdxdna: Guard management mailbox channel cleanup against NULL pointer

> A local attacker can cause a denial of service in the Linux kernel by triggering a NULL pointer dereference in the AMD XDNA driver cleanup path.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** BELL-CVE-2026-80657, DEBIAN-CVE-2026-80657, GHSA-hwpp-gg7q-6q46, UBUNTU-CVE-2026-80657

## What is CVE-2026-80657?

CVE-2026-80657 is a vulnerability in Linux, published on 28 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:

accel/amdxdna: Guard management mailbox channel cleanup against NULL pointer

The management mailbox channel cleanup helpers can be called from
error handling paths when mgmt_chann has already been destroyed.

Add NULL checks to xdna_mailbox_free_channel() and
xdna_mailbox_stop_channel() so the cleanup path safely returns instead
of dereferencing a NULL mailbox channel pointer.

## Which versions are affected by CVE-2026-80657?


## How do I fix CVE-2026-80657?

Apply the vendor's patch.

## Is CVE-2026-80657 being exploited?

There is no known exploitation of CVE-2026-80657 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80657 and fix it if it is affected.

What it is: CVE-2026-80657 is a vulnerability in Linux, published on 28 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-2026-80657 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-2026-80657/ (Markdown: https://insights.sbomify.com/CVE-2026-80657/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80657
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80657
- OSV: https://osv.dev/vulnerability/CVE-2026-80657

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80657/
Summaries are generated and may contain mistakes; the official description above is the record.