# CVE-2026-72229: batman-adv: clean untagged VLAN on netdev registration failure

> A memory leak in the Linux kernel batman-adv module can lead to resource exhaustion and denial of service when netdev registration fails.

- **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:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-72229, DEBIAN-CVE-2026-72229, GHSA-7p74-4rvh-gr76, UBUNTU-CVE-2026-72229

## What is CVE-2026-72229?

CVE-2026-72229 is a memory corruption vulnerability in Linux, published on 15 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:

batman-adv: clean untagged VLAN on netdev registration failure

When an mesh interface is registered, it creates an untagged struct
batadv_meshif_vlan on top of it via the NETDEV_REGISTER notifier. But in
this process, another receiver of this notification can veto the
registration. The netdev registration will be aborted because of this veto.

The register_netdevice() call will try to clean up the net_device using
unregister_netdevice_queue() - which only uses the .priv_destructor to
free private resources. In this situation, .dellink will not be called.

The cleanup of the untagged batadv_meshif_vlan must thefore be done in the
destructor to avoid a leak of this object.

## Which versions are affected by CVE-2026-72229?


## How do I fix CVE-2026-72229?

Apply the vendor's patch.

## Is CVE-2026-72229 being exploited?

There is no known exploitation of CVE-2026-72229 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72229 and fix it if it is affected.

What it is: CVE-2026-72229 is a memory corruption vulnerability in Linux, published on 15 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-2026-72229 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-2026-72229/ (Markdown: https://insights.sbomify.com/CVE-2026-72229/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72229
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72229
- OSV: https://osv.dev/vulnerability/CVE-2026-72229

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72229/
Summaries are generated and may contain mistakes; the official description above is the record.