# CVE-2026-72226: batman-adv: tt: prevent TVLV OOB check overflow

> An integer overflow in the batman-adv kernel module allows bypassing bounds checks, potentially leading to out-of-bounds access and system compromise.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72226, DEBIAN-CVE-2026-72226, GHSA-5r79-5r2g-4hhm, UBUNTU-CVE-2026-72226

## What is CVE-2026-72226?

CVE-2026-72226 is a critical vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

batman-adv: tt: prevent TVLV OOB check overflow

A TT unicast TVLV contains the number of VLANs stored in it. This number is
an u16 and gets multiplied by the size of the struct
batadv_tvlv_tt_vlan_data (8 bytes). The size can therefore overflow the u16
used to store the tt_vlan_len. All additional safety checks to prevent
out-of-bounds access of the TVLV buffer are invalid due to this overflow.

Using size_t prevents this overflow and ensures that the safety checks
compare against the actual buffer requirements.

## Which versions are affected by CVE-2026-72226?


## How do I fix CVE-2026-72226?

Apply the vendor's patch.

## Is CVE-2026-72226 being exploited?

There is no known exploitation of CVE-2026-72226 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72226 and fix it if it is affected.

What it is: CVE-2026-72226 is a critical vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72226 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-2026-72226/ (Markdown: https://insights.sbomify.com/CVE-2026-72226/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72226
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72226
- OSV: https://osv.dev/vulnerability/CVE-2026-72226

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72226/
Summaries are generated and may contain mistakes; the official description above is the record.