# CVE-2026-90349: wifi: mt76: mt7996: fix out-of-bounds link array access in mt7996_tx()

> An out-of-bounds array access in the mt7996 WiFi driver can cause a kernel crash or leak memory when handling unspecified link IDs.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-90349, DEBIAN-CVE-2026-90349, GHSA-763f-7f65-3wmx, UBUNTU-CVE-2026-90349

## What is CVE-2026-90349?

CVE-2026-90349 is a memory corruption vulnerability in Linux, published on 17 Sep 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: mt76: mt7996: fix out-of-bounds link array access in mt7996_tx()

When mac80211 leaves the link unspecified, mt7996_tx() substitutes the
primary link id of the station or vif. That value is
IEEE80211_LINK_UNSPECIFIED (0xf) until the first link has been added,
and it is then used unchecked to index vif->link_conf[],
mvif->mt76.link[] and sta->link[], all of which hold
IEEE80211_MLD_MAX_NUM_LINKS (15) entries.

Clamp the primary link id to the default link before using it, and use
the clamped value for the link_sta fallback as well.

## Which versions are affected by CVE-2026-90349?


## How do I fix CVE-2026-90349?

Apply the vendor's patch.

## Is CVE-2026-90349 being exploited?

There is no known exploitation of CVE-2026-90349 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90349 and fix it if it is affected.

What it is: CVE-2026-90349 is a memory corruption vulnerability in Linux, published on 17 Sep 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-2026-90349 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-2026-90349/ (Markdown: https://insights.sbomify.com/CVE-2026-90349/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90349
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90349
- OSV: https://osv.dev/vulnerability/CVE-2026-90349

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90349/
Summaries are generated and may contain mistakes; the official description above is the record.