# CVE-2026-46233: batman-adv: bla: only purge non-released claims

> A race condition in the batman-adv module can cause a null pointer dereference, leading to a kernel crash and denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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 May 2026
- **Updated:** 14 Jun 2026
- **Also known as:** AZL-88893, BELL-CVE-2026-46233, DEBIAN-CVE-2026-46233, GHSA-vvwr-mg55-mhmm, ROOT-OS-DEBIAN-11-CVE-2026-46233, ROOT-OS-DEBIAN-12-CVE-2026-46233, ROOT-OS-UBUNTU-2204-CVE-2026-46233, ROOT-OS-UBUNTU-2404-CVE-2026-46233, UBUNTU-CVE-2026-46233

## What is CVE-2026-46233?

CVE-2026-46233 is a medium-severity vulnerability in Linux kernel, published on 28 May 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:

batman-adv: bla: only purge non-released claims

When batadv_bla_purge_claims() goes through the list of claims, it is only
traversing the hash list with an rcu_read_lock(). Due to a potential
parallel batadv_claim_put(), it can happen that it encounters a claim which
was actually in the process of being released+freed by
batadv_claim_release(). In this case, backbone_gw is set to NULL before the
delayed RCU kfree is started. Calling batadv_bla_claim_get_backbone_gw() is
then no longer allowed because it would cause a NULL-ptr derefence.

To avoid this, only claims with a valid reference counter must be purged.
All others are already taken care of.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-46233?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46233?

Apply the vendor's patch.

## Is CVE-2026-46233 being exploited?

There is no known exploitation of CVE-2026-46233 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46233 and fix it if it is affected.

What it is: CVE-2026-46233 is a medium-severity vulnerability in Linux kernel, published on 28 May 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-2026-46233 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-46233/ (Markdown: https://insights.sbomify.com/CVE-2026-46233/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46233
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46233
- OSV: https://osv.dev/vulnerability/CVE-2026-46233

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46233/
Summaries are generated and may contain mistakes; the official description above is the record.