CVE-2026-20490 Denial of service in MediaTek chipset

Medium 4.4 Published 3 Aug 2026 Updated 3 Aug 2026

A missing bounds check in MediaTek chipset firmware allows local attackers with System privileges to cause a denial of service.

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-2026-20490?

CVE-2026-20490 is a medium-severity denial of service 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 ccci, there is a possible out of bounds read 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: ALPS10981501; Issue ID: MSV-7669.

Weakness: CWE-125

Which versions are affected by CVE-2026-20490?

It affects 5 products.

Products include Mediatek Mt6813 Firmware, Mediatek Mt6982vb Firmware, Mediatek Mt6986 Firmware, Mediatek Mt6986d Firmware, Mediatek Mt6988 Firmware.

How do I fix CVE-2026-20490?

No fix has been published for CVE-2026-20490 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-20490 being exploited?

There is no known exploitation of CVE-2026-20490 in the wild and no public exploit code.

Sources

Also known as GHSA-r43r-m9g7-qp49.