# CVE-2026-64223: wifi: mac80211: consume only present negotiated TTLM maps

> A flaw in the Linux kernel Wi-Fi driver allows out-of-bounds reads when parsing sparse TTLM maps, potentially disclosing memory contents.

- **Severity:** High 8.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **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:** 24 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-64223, DEBIAN-CVE-2026-64223, GHSA-m9jr-3w64-2f4w, ROOT-OS-UBUNTU-2204-CVE-2026-64223, UBUNTU-CVE-2026-64223

## What is CVE-2026-64223?

CVE-2026-64223 is a high-severity vulnerability in Linux kernel, published on 24 Jul 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: consume only present negotiated TTLM maps

ieee80211_tid_to_link_map_size_ok() validates negotiated TTLM elements
against the number of link-map entries indicated by link_map_presence.
ieee80211_parse_neg_ttlm() must consume the same layout.

The parser advanced its cursor for every TID, including TIDs whose
presence bit is clear and therefore have no map bytes in the element.
A sparse map can then make a later present TID read past the validated
element.

The bad bytes land in neg_ttlm->{up,down}link[tid] but are gated by
valid_links before being applied to driver state, so a peer cannot
turn the read into a policy change.  Under KUnit + KASAN with an
exact-sized element allocation the OOB read is reported as a
slab-out-of-bounds; whether the same trigger fires under the
production RX path depends on surrounding allocator state.

Advance the cursor only when the current TID has a map present.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-64223?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64223?

Apply the vendor's patch.

## Is CVE-2026-64223 being exploited?

There is no known exploitation of CVE-2026-64223 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64223 and fix it if it is affected.

What it is: CVE-2026-64223 is a high-severity vulnerability in Linux kernel, published on 24 Jul 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-2026-64223 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-64223/ (Markdown: https://insights.sbomify.com/CVE-2026-64223/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64223
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64223
- OSV: https://osv.dev/vulnerability/CVE-2026-64223

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64223/
Summaries are generated and may contain mistakes; the official description above is the record.