# CVE-2026-74425: afs: handle CB.InitCallBackState3 requests without a server record

> A missing check in the Linux kernel AFS callback handler can cause a null pointer dereference, leading to a denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-74425, DEBIAN-CVE-2026-74425, GHSA-pvfc-84wr-qwjc, UBUNTU-CVE-2026-74425

## What is CVE-2026-74425?

CVE-2026-74425 is a high-severity vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

afs: handle CB.InitCallBackState3 requests without a server record

The cache manager callback path now attaches the server record to an
incoming call through the rxrpc peer's app data.  That association is
not guaranteed to exist for every callback request, and most callback
handlers already tolerate that case.

Make CB.InitCallBackState3 follow the same pattern by checking whether a
server record was attached before using it.  If the peer is not mapped
to a server record, trace the request and ignore it, matching the
existing behaviour for other unmatched callback requests.

This keeps the callback handler consistent with the rest of the cache
manager service and avoids depending on peer state that may not be
available for a given request.

## Which versions are affected by CVE-2026-74425?


## How do I fix CVE-2026-74425?

Apply the vendor's patch.

## Is CVE-2026-74425 being exploited?

There is no known exploitation of CVE-2026-74425 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74425 and fix it if it is affected.

What it is: CVE-2026-74425 is a high-severity vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74425 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-2026-74425/ (Markdown: https://insights.sbomify.com/CVE-2026-74425/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74425
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74425
- OSV: https://osv.dev/vulnerability/CVE-2026-74425

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74425/
Summaries are generated and may contain mistakes; the official description above is the record.