# CVE-2026-90372: wifi: mt76: mt7915: avoid nss underflow in mt7915_mcu_get_sta_nss

> An integer underflow in the mt7915 WiFi driver can cause invalid beamforming data to be sent to firmware, potentially leading to system instability or denial of service.

- **Severity:** High 7.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102381, BELL-CVE-2026-90372, DEBIAN-CVE-2026-90372, GHSA-934p-6j28-7ggx, UBUNTU-CVE-2026-90372

## What is CVE-2026-90372?

CVE-2026-90372 is a high-severity 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: avoid nss underflow in mt7915_mcu_get_sta_nss

If a peer's VHT/HE MCS map has no supported spatial stream (all fields
0x3), the loop exits with nss == 0 and the function returned (u8)-1 (255),
which was then written into the firmware sta_rec_bf beamforming fields.
Clamp the result to 0.

## Which versions are affected by CVE-2026-90372?


## How do I fix CVE-2026-90372?

Apply the vendor's patch.

## Is CVE-2026-90372 being exploited?

There is no known exploitation of CVE-2026-90372 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90372 and fix it if it is affected.

What it is: CVE-2026-90372 is a high-severity 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-2026-90372 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-2026-90372/ (Markdown: https://insights.sbomify.com/CVE-2026-90372/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90372
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90372
- OSV: https://osv.dev/vulnerability/CVE-2026-90372

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90372/
Summaries are generated and may contain mistakes; the official description above is the record.