CVE-2026-20457 Null dereference in MediaTek chipset
A null pointer dereference in MediaTek modem firmware allows remote attackers to cause a system crash via a rogue base station.
- 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-2026-20457?
CVE-2026-20457 is a medium-severity vulnerability in MediaTek, Inc. MediaTek chipset, published on 1 Jul 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 improper input validation. 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: MOLY01826924; Issue ID: MSV-7301.
Weakness: CWE-476
Which versions are affected by CVE-2026-20457?
How do I fix CVE-2026-20457?
Apply the vendor's patch.
Is CVE-2026-20457 being exploited?
There is no known exploitation of CVE-2026-20457 in the wild and no public exploit code.
Sources
Also known as A-509305911, ASB-A-509305911, GHSA-r5cc-gr9f-ch8c, M-MOLY01826924.