CVE-2026-20535 Missing authorization in MediaTek chipset

Medium 6.7 Published 5 Oct 2026 Updated 6 Oct 2026

A missing permission check in MediaTek chipset firmware allows local attackers with System privileges to escalate privileges further.

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-2026-20535?

CVE-2026-20535 is a medium-severity missing authorization 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 aidl, there is a possible escalation of privilege due to a missing permission 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: ALPS11185216; Issue ID: MSV-9039.

Weakness: CWE-862

Which versions are affected by CVE-2026-20535?

It affects 12 products.

Products include Mediatek Mt6878 Firmware, Mediatek Mt6881 Firmware, Mediatek Mt6899 Firmware, Mediatek Mt6989 Firmware, Mediatek Mt6991 Firmware, Mediatek Mt6993 Firmware and 6 more.

How do I fix CVE-2026-20535?

No fix has been published for CVE-2026-20535 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-20535 being exploited?

There is no known exploitation of CVE-2026-20535 in the wild and no public exploit code.

Sources

Also known as GHSA-8mmg-g9gw-84mh.