CVE-2026-20521 Memory corruption in MediaTek chipset

High 8.4 Published 5 Oct 2026 Updated 6 Oct 2026

A missing bounds check in the Video HAL allows local attackers to escalate privileges without user interaction or additional execution rights.

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

What is CVE-2026-20521?

CVE-2026-20521 is a high-severity memory corruption vulnerability in MediaTek, Inc. MediaTek chipset, published on 5 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In Video HAL, there is a possible escalation of privilege due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS11375674; Issue ID: MSV-9571.

Weakness: CWE-121

Which versions are affected by CVE-2026-20521?

It affects 48 products.

Products include Mediatek Mt2718 Firmware, Mediatek Mt6768 Firmware, Mediatek Mt6769 Firmware, Mediatek Mt6781 Firmware, Mediatek Mt6789 Firmware, Mediatek Mt6833 Firmware and 42 more.

How do I fix CVE-2026-20521?

No fix has been published for CVE-2026-20521 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-2026-20521 being exploited?

There is no known exploitation of CVE-2026-20521 in the wild and no public exploit code.

Sources

Also known as GHSA-qpf3-2wfg-8hrm.