CVE-2026-20462 is a heap buffer overflow vulnerability (CWE-122) in the Telephony functionality of various MediaTek chipsets. The flaw leads to possible memory corruption that could be exploited by a local attacker who already has System privileges to escalate their privileges further. Exploitation does not require user interaction. The vulnerability affects a broad range of MediaTek chipset models explicitly enumerated in the affectedVersions field. No CVSS score or vendor remediation details are currently available.

The vulnerability allows local privilege escalation by causing memory corruption through a heap buffer overflow in the Telephony component. Since the attacker must already have System privileges, the impact is limited to privilege escalation rather than initial compromise. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or remediation level has been published. Users and administrators should monitor MediaTek advisories for updates and apply patches once available.