# CVE-2026-20456: Memory corruption in MediaTek chipset

> A missing bounds check in the MediaTek WLAN STA driver allows local attackers to cause a system crash, requiring user privileges but no interaction.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Jun 2026
- **Updated:** 1 Jun 2026
- **Also known as:** GHSA-v8qh-hh5q-9vc3

## What is CVE-2026-20456?

CVE-2026-20456 is a medium-severity memory corruption vulnerability in MediaTek, Inc. MediaTek chipset, published on 1 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In wlan STA driver, there is a possible system crash due to a missing bounds check. This could lead to local denial of service with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00480851; Issue ID: MSV-6338.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-20456?

It affects 6 products.


Products: Mediatek Mt7902 Firmware, Mediatek Mt7920 Firmware, Mediatek Mt7921 Firmware, Mediatek Mt7922 Firmware, Mediatek Mt7925 Firmware, Mediatek Mt7927 Firmware.

## How do I fix CVE-2026-20456?

No fix has been published for CVE-2026-20456 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20456 being exploited?

There is no known exploitation of CVE-2026-20456 in the wild and no public exploit code.

## Other vulnerabilities in MediaTek, Inc. MediaTek chipset

- [CVE-2025-20672](https://insights.sbomify.com/CVE-2025-20672/): Memory corruption in MT7902, MT7921, MT7922, MT7925, MT7927 (critical 9.8)
- [CVE-2026-20495](https://insights.sbomify.com/CVE-2026-20495/): Missing authorization in MediaTek chipset (high 7.8)
- [CVE-2026-20482](https://insights.sbomify.com/CVE-2026-20482/): Denial of service in MediaTek chipset (medium 6.5)
- [CVE-2025-20673](https://insights.sbomify.com/CVE-2025-20673/): Null dereference in MT7902, MT7921, MT7922, MT7925, MT7927 (medium 5.5)
- [CVE-2025-20675](https://insights.sbomify.com/CVE-2025-20675/): Null dereference in MT7902, MT7921, MT7922, MT7925, MT7927 (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20456 and fix it if it is affected.

What it is: CVE-2026-20456 is a medium-severity memory corruption vulnerability in MediaTek, Inc. MediaTek chipset, published on 1 Jun 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-2026-20456 in the wild and no public exploit code.

Affected product: MediaTek, Inc. MediaTek chipset. 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-2026-20456/ (Markdown: https://insights.sbomify.com/CVE-2026-20456/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20456
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20456
- OSV: https://osv.dev/vulnerability/CVE-2026-20456

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20456/
Summaries are generated and may contain mistakes; the official description above is the record.