# CVE-2026-80599: batman-adv: dat: ensure accessible eth_hdr proto field

> A missing bounds check in the batman-adv kernel module allows out-of-bounds memory access, potentially causing crashes or information leaks.

- **Severity:** High 8.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/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:** 28 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-80599, DEBIAN-CVE-2026-80599, GHSA-j72w-p49p-cjqq, UBUNTU-CVE-2026-80599

## What is CVE-2026-80599?

CVE-2026-80599 is a high-severity memory corruption vulnerability in Linux, published on 28 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: dat: ensure accessible eth_hdr proto field

When batadv_get_vid() accesses the proto field of the ethernet header, it
is not checking if the data itself is accessible. The caller is responsible
for it. But in contrast to other call sites, batadv_dat_get_vid() and its
caller didn't make sure this is true. This could have caused an
out-of-bounds access.

## Which versions are affected by CVE-2026-80599?


## How do I fix CVE-2026-80599?

Apply the vendor's patch.

## Is CVE-2026-80599 being exploited?

There is no known exploitation of CVE-2026-80599 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80599 and fix it if it is affected.

What it is: CVE-2026-80599 is a high-severity memory corruption vulnerability in Linux, published on 28 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-2026-80599 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-2026-80599/ (Markdown: https://insights.sbomify.com/CVE-2026-80599/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80599
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80599
- OSV: https://osv.dev/vulnerability/CVE-2026-80599

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80599/
Summaries are generated and may contain mistakes; the official description above is the record.