# CVE-2026-20542: Use after free in MediaTek chipset

> A use-after-free vulnerability in MediaTek chipsets allows local privilege escalation for attackers with System privileges.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-2v6f-cp2c-9f7v

## What is CVE-2026-20542?

CVE-2026-20542 is a medium-severity use after free vulnerability in MediaTek, Inc. MediaTek chipset, published on 5 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In apusys, there is a possible memory corruption due to use after free. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11076799; Issue ID: MSV-8143.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-20542?

It affects 19 products.


Products: Mediatek Mt2718 Firmware, Mediatek Mt6878 Firmware, Mediatek Mt6897 Firmware, Mediatek Mt6899 Firmware, Mediatek Mt6989 Firmware, Mediatek Mt6991 Firmware, Mediatek Mt8171 Firmware, Mediatek Mt8188 Firmware, Mediatek Mt8189 Firmware, Mediatek Mt8196 Firmware, Mediatek Mt8370 Firmware, Mediatek Mt8371 Firmware, Mediatek Mt8390 Firmware, Mediatek Mt8391 Firmware, Mediatek Mt8395 Firmware, Mediatek Mt8678 Firmware, Mediatek Mt8792 Firmware, Mediatek Mt8793 Firmware, Mediatek Mt8796 Firmware.

## How do I fix CVE-2026-20542?

No fix has been published for CVE-2026-20542 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20542 being exploited?

There is no known exploitation of CVE-2026-20542 in the wild and no public exploit code.

## Other vulnerabilities in MediaTek, Inc. MediaTek chipset

- [CVE-2026-20586](https://insights.sbomify.com/CVE-2026-20586/): Memory corruption in MediaTek chipset (high 8.8)
- [CVE-2026-20521](https://insights.sbomify.com/CVE-2026-20521/): Memory corruption in MediaTek chipset (high 8.4)
- [CVE-2026-20501](https://insights.sbomify.com/CVE-2026-20501/): Memory corruption in MediaTek chipset (high 8.4)
- [CVE-2026-20502](https://insights.sbomify.com/CVE-2026-20502/): Memory corruption in MediaTek chipset (high 8.4)
- [CVE-2026-20530](https://insights.sbomify.com/CVE-2026-20530/): Memory corruption in MediaTek chipset (medium 6.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20542 and fix it if it is affected.

What it is: CVE-2026-20542 is a medium-severity use after free vulnerability in MediaTek, Inc. MediaTek chipset, published on 5 Oct 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-2026-20542 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-2026-20542/ (Markdown: https://insights.sbomify.com/CVE-2026-20542/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20542
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20542
- OSV: https://osv.dev/vulnerability/CVE-2026-20542

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20542/
Summaries are generated and may contain mistakes; the official description above is the record.