CVE-2026-20502: CWE-122 Heap-based Buffer Overflow in MediaTek, Inc. MediaTek chipset

This vulnerability (CVE-2026-20502) involves a heap-based buffer overflow (CWE-122) in the MediaTek chipset's video decoder (vdec) component. The root cause is a missing bounds check that permits out-of-bounds memory writes. Successful exploitation can result in local escalation of privileges without needing additional execution privileges or user interaction. The affected chipset models include a wide range of MediaTek SoCs such as MT2718, MT6580, MT6739, MT6761, MT6765, MT6768, MT6769, MT6779, MT6781, MT6785, MT6789, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6877, MT6878, MT6879, MT6881, MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899, MT6983, MT6985, MT6989, MT6991, MT6993, MT8126, MT8171, MT8186, MT8188, MT8189, MT8195, MT8196, MT8367, MT8391, MT8395, MT8668, MT8676, MT8678, MT8696, MT8781, MT8792, MT8799, and MT8910. The CVSS vector indicates low attack complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.

The vulnerability allows an attacker with local access to perform out-of-bounds writes in the heap memory of the video decoder component, leading to local privilege escalation. This can compromise system confidentiality, integrity, and availability. No additional execution privileges or user interaction are required, increasing the risk of exploitation in local attack scenarios. There are no known exploits in the wild as of the provided data.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The provided data includes a Patch ID (ALPS11262030) and Issue ID (MSV-9196), but no direct patch links or vendor advisory content confirming availability of a fix. Users and administrators should monitor MediaTek's official advisories for updates and apply patches once available.