# CVE-2026-98810: wifi: mac80211: fix slab-out-of-bounds read in ieee80211_monitor_select_queue()

> A local attacker can trigger a slab-out-of-bounds read in the Linux kernel WiFi subsystem, potentially causing a crash or leaking memory.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-108641, BELL-CVE-2026-98810, DEBIAN-CVE-2026-98810, GHSA-8wg2-h9c3-q8hh, UBUNTU-CVE-2026-98810

## What is CVE-2026-98810?

CVE-2026-98810 is a memory corruption vulnerability in Linux, published on 18 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: mac80211: fix slab-out-of-bounds read in ieee80211_monitor_select_queue()

ieee80211_monitor_select_queue() validates the skb length using skb->len
before dereferencing pointers into skb->data to access the 802.11 header.
However, skb->len includes data in both the linear head buffer and
non-linear fragments/pages. When AF_PACKET sends a packet large enough to
become non-linear, the 802.11 header at skb->data + len_rthdr may extend
past the linear head buffer even though skb->len appears sufficient.

This leads to a slab-out-of-bounds read when accessing hdr->frame_control,
as the kernel reads beyond the allocated skb head buffer:

  BUG: KASAN: slab-out-of-bounds in ieee80211_monitor_select_queue+0x1ed/0x220

syzbot has hit the same issues.

Fix this by checking skb_headlen(skb) (which gives the length of the
linear data region) instead of skb->len before dereferencing skb->data
pointers. This ensures the required bytes are actually present in the
linear portion of the skb.

Apply the same fix to ieee80211_validate_radiotap_len() which has the
same class of bug: it uses skb->len to validate accesses to skb->data,
and to the corresponding checks in ieee80211_monitor_start_xmit(): for
drivers advertising NETIF_F_SG the skb is not linearized before
ndo_start_xmit, so the 802.11 header can be read past the linear
buffer there as well.

## Which versions are affected by CVE-2026-98810?


## How do I fix CVE-2026-98810?

Apply the vendor's patch.

## Is CVE-2026-98810 being exploited?

There is no known exploitation of CVE-2026-98810 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98810 and fix it if it is affected.

What it is: CVE-2026-98810 is a memory corruption vulnerability in Linux, published on 18 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-2026-98810 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-2026-98810/ (Markdown: https://insights.sbomify.com/CVE-2026-98810/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98810
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98810
- OSV: https://osv.dev/vulnerability/CVE-2026-98810

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98810/
Summaries are generated and may contain mistakes; the official description above is the record.