CVE-2026-20493 Memory corruption in MediaTek chipset

Medium 4.4 Published 3 Aug 2026 Updated 3 Aug 2026

A missing bounds check in MediaTek chipset Wi-Fi firmware allows local denial of service for attackers with System privileges.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-20493?

CVE-2026-20493 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 wifi, there is a possible out of bounds write due to a missing bounds check. This could lead to local denial of service if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: BORA00154903; Issue ID: MSV-7575.

Weakness: CWE-787

Which versions are affected by CVE-2026-20493?

It affects 3 products.

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

How do I fix CVE-2026-20493?

No fix has been published for CVE-2026-20493 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-2026-20493 being exploited?

There is no known exploitation of CVE-2026-20493 in the wild and no public exploit code.

Sources

Also known as GHSA-pv3g-w5cg-j5g3.