# CVE-2026-98345: wifi: cfg80211: check IP header size in cfg80211_classify8021d()

> A missing IP header size check in the Linux kernel Wi-Fi subsystem allows reading uninitialized memory, potentially disclosing sensitive kernel data.

- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-105990, BELL-CVE-2026-98345, DEBIAN-CVE-2026-98345, GHSA-vm8v-8wgx-pm6r, UBUNTU-CVE-2026-98345

## What is CVE-2026-98345?

CVE-2026-98345 is a vulnerability in Linux, published on 6 Oct 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:

wifi: cfg80211: check IP header size in cfg80211_classify8021d()

A frame that looks like IP can be transmitted, but be too short, so
the DS field is read incorrectly:

  BUG: KMSAN: uninit-value in cfg80211_classify8021d+0x99d/0x12b0 net/wireless/util.c:1027
   cfg80211_classify8021d+0x99d/0x12b0 net/wireless/util.c:1027
   ieee80211_select_queue+0x37a/0x9e0 net/mac80211/wme.c:180
   __ieee80211_subif_start_xmit+0x60f/0x1d90 net/mac80211/tx.c:4304
   ieee80211_subif_start_xmit+0xa8/0x6d0 net/mac80211/tx.c:4538
   ...
   packet_sendmsg+0x9173/0xa2a0 net/packet/af_packet.c:3108

Use skb_header_pointer() like the MPLS case.

## Which versions are affected by CVE-2026-98345?


## How do I fix CVE-2026-98345?

Apply the vendor's patch.

## Is CVE-2026-98345 being exploited?

There is no known exploitation of CVE-2026-98345 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98345 and fix it if it is affected.

What it is: CVE-2026-98345 is a vulnerability in Linux, published on 6 Oct 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-2026-98345 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-2026-98345/ (Markdown: https://insights.sbomify.com/CVE-2026-98345/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98345
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98345
- OSV: https://osv.dev/vulnerability/CVE-2026-98345

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98345/
Summaries are generated and may contain mistakes; the official description above is the record.