# CVE-2026-20494: Information disclosure in MediaTek chipset

> A missing bounds check in MediaTek chipset Wi-Fi firmware allows local attackers with System privileges to read out-of-bounds memory, disclosing sensitive information.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **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:** 3 Aug 2026
- **Updated:** 3 Aug 2026
- **Also known as:** GHSA-p939-jv8f-p7rc

## What is CVE-2026-20494?

CVE-2026-20494 is a medium-severity vulnerability in MediaTek, Inc. MediaTek chipset, published on 3 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In wifi, there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS10960006 /  BORA00155314, BORA00155001, BORA00154907; Issue ID: MSV-7570.

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

## Which versions are affected by CVE-2026-20494?

It affects 3 products.


Products: Mediatek Mt6890 Firmware, Mediatek Mt6988 Firmware, Mediatek Mt6990 Firmware.

## How do I fix CVE-2026-20494?

No fix has been published for CVE-2026-20494 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20494 being exploited?

There is no known exploitation of CVE-2026-20494 in the wild and no public exploit code.

## Other vulnerabilities in MediaTek, Inc. MediaTek chipset

- [CVE-2026-20452](https://insights.sbomify.com/CVE-2026-20452/): Memory corruption in MediaTek chipset (high 8.0)
- [CVE-2026-20493](https://insights.sbomify.com/CVE-2026-20493/): Memory corruption in MediaTek chipset (medium 4.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20494 and fix it if it is affected.

What it is: CVE-2026-20494 is a medium-severity vulnerability in MediaTek, Inc. MediaTek chipset, published on 3 Aug 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-2026-20494 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-2026-20494/ (Markdown: https://insights.sbomify.com/CVE-2026-20494/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20494
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20494
- OSV: https://osv.dev/vulnerability/CVE-2026-20494

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20494/
Summaries are generated and may contain mistakes; the official description above is the record.