CVE-2026-20459 Denial of service in MediaTek chipset
Remote attackers can cause system crashes in MediaTek chipsets by connecting a device to a rogue base station, requiring no user interaction or privileges.
- 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-2026-20459?
CVE-2026-20459 is a medium-severity denial of service 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: MOLY01816800; Issue ID: MSV-6842.
Weakness: CWE-288
Which versions are affected by CVE-2026-20459?
How do I fix CVE-2026-20459?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-20459 being exploited?
There is no known exploitation of CVE-2026-20459 in the wild and no public exploit code.
Sources
Also known as A-509319284, ASB-A-509319284, GHSA-67vv-7c97-f7h6, M-MOLY01816800.