# CVE-2026-98699: wifi: mac80211: fix mesh fast xmit path deletion UAF

> A use-after-free in the Linux kernel's mac80211 mesh networking allows attackers to cause denial of service or execute arbitrary code.

- **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:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-109239, BELL-CVE-2026-98699, DEBIAN-CVE-2026-98699, GHSA-5j8p-334x-vh85, UBUNTU-CVE-2026-98699

## What is CVE-2026-98699?

CVE-2026-98699 is an use after free 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 mesh fast xmit path deletion UAF

mesh_fast_tx_cache() stores raw mesh_path pointers. Path deletion
flushes the cache and then frees the path with kfree_rcu(), but a
lookup that already holds the path can insert a new cache entry
after the flush. The cache then points at freed memory.

Set MESH_PATH_DELETED before flushing, and skip inserting a cache
entry if the path or MPP path is already deleted. Check this under
the cache walk lock so it is ordered with the flush. Use WRITE_ONCE()
for the deletion flag updates because the cache check reads flags
without taking state_lock.

## Which versions are affected by CVE-2026-98699?


## How do I fix CVE-2026-98699?

Apply the vendor's patch.

## Is CVE-2026-98699 being exploited?

There is no known exploitation of CVE-2026-98699 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98699 and fix it if it is affected.

What it is: CVE-2026-98699 is an use after free 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-2026-98699 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-2026-98699/ (Markdown: https://insights.sbomify.com/CVE-2026-98699/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98699
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98699
- OSV: https://osv.dev/vulnerability/CVE-2026-98699

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98699/
Summaries are generated and may contain mistakes; the official description above is the record.