# CVE-2026-90159: bpf: Disallow bpf_{g,s}etsockopt() in cgroup UNIX getname hooks

> A local attacker with high privileges can trigger a kernel warning and potential instability by calling specific BPF helpers in cgroup UNIX getname hooks.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-90159, DEBIAN-CVE-2026-90159, GHSA-rcrw-xvqq-c49m, UBUNTU-CVE-2026-90159

## What is CVE-2026-90159?

CVE-2026-90159 is a denial of service vulnerability in Linux, published on 17 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:

bpf: Disallow bpf_{g,s}etsockopt() in cgroup UNIX getname hooks

_bpf_setsockopt() and _bpf_getsockopt() call sock_owned_by_me() for
full sockets, so these helpers expect the socket lock to be held.

BPF_CGROUP_UNIX_GETPEERNAME and BPF_CGROUP_UNIX_GETSOCKNAME run BPF
programs without acquiring the socket lock. A program attached to
either hook can therefore trigger the sock_owned_by_me() warning by
calling bpf_setsockopt() or bpf_getsockopt().

Disallow bpf_setsockopt() and bpf_getsockopt() for CGROUP_UNIX_GETPEERNAME
and CGROUP_UNIX_GETSOCKNAME.

## Which versions are affected by CVE-2026-90159?


## How do I fix CVE-2026-90159?

Apply the vendor's patch.

## Is CVE-2026-90159 being exploited?

There is no known exploitation of CVE-2026-90159 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90159 and fix it if it is affected.

What it is: CVE-2026-90159 is a denial of service vulnerability in Linux, published on 17 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-2026-90159 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-2026-90159/ (Markdown: https://insights.sbomify.com/CVE-2026-90159/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90159
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90159
- OSV: https://osv.dev/vulnerability/CVE-2026-90159

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90159/
Summaries are generated and may contain mistakes; the official description above is the record.