# CVE-2026-89949: batman-adv: dat: avoid unaligned fault in IP extraction

> An unaligned memory access in the batman-adv kernel module can cause a system crash, requiring a kernel patch to fix.

- **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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101319, BELL-CVE-2026-89949, DEBIAN-CVE-2026-89949, GHSA-95x9-5832-jchc, UBUNTU-CVE-2026-89949

## What is CVE-2026-89949?

CVE-2026-89949 is a denial of service vulnerability in Linux, published on 16 Sep 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: avoid unaligned fault in IP extraction

Independent of the alignment of the ARP packet in the SKB, either the
batadv_arp_ip_src or the batadv_arp_ip_dst will have an unaligned access
(on HW without native unaligned read support).

Use get_unaligned() to handle this properly on all architectures.

## Which versions are affected by CVE-2026-89949?


## How do I fix CVE-2026-89949?

Apply the vendor's patch.

## Is CVE-2026-89949 being exploited?

There is no known exploitation of CVE-2026-89949 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89949 and fix it if it is affected.

What it is: CVE-2026-89949 is a denial of service vulnerability in Linux, published on 16 Sep 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-2026-89949 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-2026-89949/ (Markdown: https://insights.sbomify.com/CVE-2026-89949/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89949
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89949
- OSV: https://osv.dev/vulnerability/CVE-2026-89949

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89949/
Summaries are generated and may contain mistakes; the official description above is the record.