# CVE-2026-98709: wifi: mac80211: count only matching reservations in reserved switch

> A use-after-free in the Linux kernel Wi-Fi subsystem allows attackers to cause denial of service or execute code via crafted channel context reservations.

- **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-108881, BELL-CVE-2026-98709, DEBIAN-CVE-2026-98709, GHSA-g34c-vjm7-4vq5, UBUNTU-CVE-2026-98709

## What is CVE-2026-98709?

CVE-2026-98709 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: count only matching reservations in reserved switch

ieee80211_vif_use_reserved_switch() validates a replacement by counting
assigned links on ctx->replace_ctx and treating reservations too
broadly. A link can still be assigned to the old channel context while
holding a reservation that belongs to a different replacement
operation.

That can make the current replacement appear complete too early. If
another link finalizes first, the function can free the
WILL_BE_REPLACED chanctx while the unmatched link and driver still use
it, leading to a use-after-free in later beacon generation.

Require an in-place reservation to point at the current replacement
context, and require the reserved and assigned contexts to be the
matching replacement pair, before counting or moving the link.

## Which versions are affected by CVE-2026-98709?


## How do I fix CVE-2026-98709?

Apply the vendor's patch.

## Is CVE-2026-98709 being exploited?

There is no known exploitation of CVE-2026-98709 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98709 and fix it if it is affected.

What it is: CVE-2026-98709 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-2026-98709 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-2026-98709/ (Markdown: https://insights.sbomify.com/CVE-2026-98709/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98709
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98709
- OSV: https://osv.dev/vulnerability/CVE-2026-98709

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98709/
Summaries are generated and may contain mistakes; the official description above is the record.