CVE-2026-20423 Memory corruption in MediaTek chipset

High 7.8 Published 2 Mar 2026 Updated 30 Mar 2026

A missing bounds check in the MediaTek WLAN STA driver allows local attackers to escalate 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: None listed

What is CVE-2026-20423?

CVE-2026-20423 is a high-severity memory corruption vulnerability in MediaTek, Inc. MediaTek chipset, published on 2 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In wlan STA driver, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00465314; Issue ID: MSV-4956.

Weakness: CWE-787, CWE-749

Which versions are affected by CVE-2026-20423?

It affects 1 product.

Products include Mediatek Nbiot Sdk.

How do I fix CVE-2026-20423?

No fix has been published for CVE-2026-20423 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-2026-20423 being exploited?

There is no known exploitation of CVE-2026-20423 in the wild and no public exploit code.

Sources

Also known as GHSA-5pr4-qmc6-fvxj.