CVE-2026-20413: 
NixOS vulnerability analysis and mitigation

CVE-2026-20413 is an out-of-bounds write vulnerability in the MediaTek imgsys component affecting Android 15.0 on specific MediaTek chipsets (MT6899, MT6991, MT8678, MT8793). The flaw stems from a missing bounds check that could allow a local attacker who has already obtained System privilege to further escalate privileges. It was published on February 2, 2026, with a patch released as part of MediaTek's February 2026 Product Security Bulletin (Patch ID: ALPS10362725; Issue ID: MSV-5694). The vulnerability carries a CVSS v3.1 base score of 6.7 (Medium) (MediaTek Bulletin, Red Hat CVE).

The root cause is classified under CWE-787 (Out-of-bounds Write) and CWE-1285 (Improper Validation of Specified Index, Position, or Offset in Input). The imgsys driver component fails to validate array indices or buffer offsets before performing write operations, enabling memory corruption beyond the intended buffer boundary. Exploitation requires the attacker to already hold System-level privilege on the device, making this a local, post-compromise escalation vector with low attack complexity and no user interaction required (MediaTek Bulletin, Red Hat CVE).

Successful exploitation could allow an attacker who already possesses System privilege to escalate further and execute arbitrary code with elevated permissions, impacting confidentiality, integrity, and availability of the affected device. The vulnerability is scoped to the local device and does not directly enable remote code execution or lateral movement across a network. Affected platforms are Android 15.0 devices running on MediaTek chipsets MT6899, MT6991, MT8678, and MT8793 (MediaTek Bulletin).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation as of the time of publication (MediaTek Bulletin). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.037%, reflecting a very low probability of exploitation in the near term. Exploitation is constrained by the prerequisite of System-level privilege, significantly limiting the attacker population.

MediaTek has released a patch (Patch ID: ALPS10362725) as part of the February 2026 Product Security Bulletin. Users and device manufacturers should apply the available OEM security update for Android 15.0 on affected chipsets (MT6899, MT6991, MT8678, MT8793) as soon as it is distributed. In the interim, organizations should monitor for suspicious privilege escalation activity on affected devices and restrict access to System-level privileges where possible (MediaTek Bulletin).