CVE-2026-20455 Memory corruption in MediaTek chipset

High 7.8 Published 1 Jun 2026 Updated 2 Jun 2026

A missing bounds check in MediaTek chipset firmware allows local privilege escalation from System privileges via an out-of-bounds write.

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

What is CVE-2026-20455?

CVE-2026-20455 is a high-severity memory corruption vulnerability in MediaTek, Inc. MediaTek chipset, published on 1 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In geniezone, there is a possible out of bounds write due to a missing bounds check. 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: ALPS10873936; Issue ID: MSV-6784.

Weakness: CWE-787

Which versions are affected by CVE-2026-20455?

It affects 36 products.

Products include Mediatek Mt6739 Firmware, Mediatek Mt6761 Firmware, Mediatek Mt6765 Firmware, Mediatek Mt6768 Firmware, Mediatek Mt6781 Firmware, Mediatek Mt6789 Firmware and 30 more.

How do I fix CVE-2026-20455?

Apply the vendor's patch.

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

Is CVE-2026-20455 being exploited?

There is no known exploitation of CVE-2026-20455 in the wild and no public exploit code.

Sources

Also known as GHSA-jf3x-c8h2-5gjj.