# CVE-2026-90373: wifi: mt76: mt7915: clear wcid mask under mutex after RCU pointer clear

> A race condition in the mt7915 WiFi driver allows concurrent interface removal and allocation to corrupt state, potentially leading to privilege escalation or denial of service.

- **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:** 21 Oct 2026
- **Also known as:** BELL-CVE-2026-90373, DEBIAN-CVE-2026-90373, GHSA-4c4x-fg8c-5526, UBUNTU-CVE-2026-90373

## What is CVE-2026-90373?

CVE-2026-90373 is a 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: mt7915: clear wcid mask under mutex after RCU pointer clear

mt7915_remove_interface() cleared the wcid mask bit with no lock held and
before clearing the RCU wcid pointer. The mask is a non-atomic RMW shared
with the allocators, which all run under dev->mt76.mutex; on DBDC the two
wiphys share one mt76_dev, so this raced add_interface/sta_add on the
other band and could leak or double-hand-out a wcid. Clearing the bit
before the RCU pointer also let a concurrent allocation reuse the index
and publish its wcid, which the subsequent NULL assignment then wiped.
Move the clear into the existing mutex section, after the RCU pointer is
cleared.

## Which versions are affected by CVE-2026-90373?


## How do I fix CVE-2026-90373?

Apply the vendor's patch.

## Is CVE-2026-90373 being exploited?

There is no known exploitation of CVE-2026-90373 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90373 and fix it if it is affected.

What it is: CVE-2026-90373 is a 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-2026-90373 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-2026-90373/ (Markdown: https://insights.sbomify.com/CVE-2026-90373/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90373
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90373
- OSV: https://osv.dev/vulnerability/CVE-2026-90373

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90373/
Summaries are generated and may contain mistakes; the official description above is the record.