CVE-2026-20478 Memory corruption in MediaTek chipset

Medium 5.5 Published 3 Aug 2026 Updated 3 Aug 2026

A heap buffer overflow in the Audio HAL allows local attackers to cause a denial of service on MediaTek chipsets.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-20478?

CVE-2026-20478 is a medium-severity memory corruption 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 Audio HAL, there is a possible out of bounds write due to a heap buffer overflow. This could lead to local denial of service with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS10981454 (Note: For MT6880, MT6890, MT6988, MT6990) / AUTO00851293 (Note: For MT2735, MT2737); Issue ID: MSV-7638.

Weakness: CWE-787

Which versions are affected by CVE-2026-20478?

It affects 6 products.

Products include Mediatek Mt2735 Firmware, Mediatek Mt2737 Firmware, Mediatek Mt6880 Firmware, Mediatek Mt6890 Firmware, Mediatek Mt6988 Firmware, Mediatek Mt6990 Firmware.

How do I fix CVE-2026-20478?

No fix has been published for CVE-2026-20478 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-20478 being exploited?

There is no known exploitation of CVE-2026-20478 in the wild and no public exploit code.

Sources

Also known as GHSA-36p8-6qw9-45qf.