# CVE-2026-98394: af_unix: Return immediately when manage_oob() returns NULL for 0-length buffer.

> A local attacker can cause a busy-wait denial of service in the Linux kernel by triggering a specific condition in the af_unix socket implementation.

- **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:** 14 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-108119, BELL-CVE-2026-98394, DEBIAN-CVE-2026-98394, GHSA-78rw-466c-3p7p, UBUNTU-CVE-2026-98394

## What is CVE-2026-98394?

CVE-2026-98394 is a denial of service vulnerability in Linux, published on 14 Oct 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:

af_unix: Return immediately when manage_oob() returns NULL for 0-length buffer.

Fahad Alharbi reported that recv(0, MSG_PEEK) triggers busy-wait
in unix_stream_read_generic() if recv() is blocking and the last
skb in the queue is MSG_OOB skb.

In such a situation, TCP returns 0 immediately regardless of
blocking or non-blocking.

Let's follow the behaviour.

## Which versions are affected by CVE-2026-98394?


## How do I fix CVE-2026-98394?

Apply the vendor's patch.

## Is CVE-2026-98394 being exploited?

There is no known exploitation of CVE-2026-98394 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98394 and fix it if it is affected.

What it is: CVE-2026-98394 is a denial of service vulnerability in Linux, published on 14 Oct 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-2026-98394 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-2026-98394/ (Markdown: https://insights.sbomify.com/CVE-2026-98394/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98394
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98394
- OSV: https://osv.dev/vulnerability/CVE-2026-98394

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98394/
Summaries are generated and may contain mistakes; the official description above is the record.