CVE-2026-20431 Denial of service in MediaTek chipset

Medium 6.5 Published 7 Apr 2026 Updated 7 Apr 2026

A logic error in MediaTek modem firmware allows remote attackers to cause a system crash via a rogue base station, requiring no user interaction.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2026-20431?

CVE-2026-20431 is a medium-severity denial of service vulnerability in MediaTek, Inc. MediaTek chipset, published on 7 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In Modem, there is a possible system crash due to a logic error. This could lead to remote denial of service, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01106496; Issue ID: MSV-4467.

Weakness: CWE-770

Which versions are affected by CVE-2026-20431?

It affects 19 products.

Products include Mediatek Mt6813 Firmware, Mediatek Mt6815 Firmware, Mediatek Mt6835 Firmware, Mediatek Mt6878 Firmware, Mediatek Mt6897 Firmware, Mediatek Mt6899 Firmware and 13 more.

How do I fix CVE-2026-20431?

Apply the vendor's patch.

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-2026-20431 being exploited?

There is no known exploitation of CVE-2026-20431 in the wild and no public exploit code.

Sources

Also known as A-480745369, ASB-A-480745369, GHSA-6pq9-8556-qr3w, M-MOLY01106496.