This vulnerability (CVE-2026-20460) involves an authentication bypass due to improper input validation in the modem of MediaTek chipsets. An attacker controlling a rogue base station can exploit this to remotely disclose information from a UE without needing extra execution privileges or user interaction. The issue is tracked under MediaTek's internal ID MSV-6788 and patch ID MOLY01811421, but no public patch or remediation guidance is currently available. The affected chipsets include a wide range of MediaTek models such as MT2735, MT6779, MT6789, MT6890, MT6980, MT8781, and others explicitly enumerated.

The impact is remote information disclosure through authentication bypass when a UE connects to a malicious base station. This could compromise sensitive data on the device without requiring user interaction or elevated privileges. There is no indication of code execution or denial of service. No known exploits are reported in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no official fix or mitigation details are provided, users and administrators should monitor MediaTek advisories for updates. Avoid connecting to untrusted or suspicious base stations where possible.