# CVE-2026-72235: batman-adv: retrieve ethhdr after potential skb realloc on RX

> A use-after-free vulnerability in the Linux kernel's batman-adv module allows attackers to cause denial of service or execute arbitrary code via crafted network packets.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72235, DEBIAN-CVE-2026-72235, GHSA-wgqg-h53f-2jvm, UBUNTU-CVE-2026-72235

## What is CVE-2026-72235?

CVE-2026-72235 is a high-severity use after free 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: retrieve ethhdr after potential skb realloc on RX

pskb_may_pull() in batadv_interface_rx() could reallocate the buffer behind
the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.

This was done correctly for the VLAN header but missed for the ethernet
header which is later used for the TT and AP isolation handling.

## Which versions are affected by CVE-2026-72235?


## How do I fix CVE-2026-72235?

Apply the vendor's patch.

## Is CVE-2026-72235 being exploited?

There is no known exploitation of CVE-2026-72235 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72235 and fix it if it is affected.

What it is: CVE-2026-72235 is a high-severity use after free 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-2026-72235 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-2026-72235/ (Markdown: https://insights.sbomify.com/CVE-2026-72235/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72235
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72235
- OSV: https://osv.dev/vulnerability/CVE-2026-72235

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72235/
Summaries are generated and may contain mistakes; the official description above is the record.