CVE-2026-20413: Google Android Privilege Escalation Flaw

CVE-2026-20413 Overview

CVE-2026-20413 is an out-of-bounds write vulnerability in the MediaTek imgsys component caused by a missing bounds check. The flaw affects Google Android 15.0 devices running on MediaTek chipsets including MT6899, MT6991, MT8678, and MT8793. An attacker who has already obtained System privilege on the device can trigger the out-of-bounds write locally without any user interaction. Successful exploitation enables local escalation of privilege, allowing code execution beyond the System privilege boundary. MediaTek tracks the fix as Patch ID ALPS10362725 and Issue ID MSV-5694, addressed in the February 2026 security bulletin.

Critical Impact

Local privilege escalation from System-level access through an out-of-bounds write in the MediaTek imgsys driver, leading to full compromise of confidentiality, integrity, and availability on affected Android devices.

Affected Products

• Google Android 15.0
• MediaTek MT6899, MT6991
• MediaTek MT8678, MT8793

Discovery Timeline

• 2026-02-02 - CVE-2026-20413 published to NVD
• 2026-02-03 - Last updated in NVD database
• February 2026 - MediaTek publishes security bulletin with Patch ID ALPS10362725

Technical Details for CVE-2026-20413

Vulnerability Analysis

The vulnerability resides in MediaTek's imgsys subsystem, which handles image signal processing on affected MediaTek SoCs. The component fails to validate input boundaries before performing a write operation, resulting in an out-of-bounds write condition classified under [CWE-787] and [CWE-1285]. An attacker writing past the allocated buffer can corrupt adjacent kernel memory structures. Because imgsys operates within kernel context, controlled memory corruption translates directly into kernel-level code execution. The attack is local and requires no user interaction, but the attacker must already hold System privilege on the target device.

Root Cause

The root cause is a missing bounds check on user-controlled input passed to the imgsys driver. The component accepts data sizes or indices without verifying they remain within the allocated buffer's limits. This improper input validation [CWE-1285] permits write operations beyond the buffer boundary [CWE-787]. The defect resides in shared MediaTek driver code, which is why multiple chipset families share the same vulnerability.

Attack Vector

Exploitation requires local access with System-level privileges already obtained, typically through a separate vulnerability or a privileged application. The attacker invokes the vulnerable imgsys interface with crafted parameters to trigger the out-of-bounds write. This bypasses the privilege boundary between the System user and the kernel, enabling kernel code execution. The vulnerability is part of a multi-stage exploit chain rather than an initial access vector.

Verified exploit code is not publicly available. Refer to the MediaTek Security Bulletin February 2026 for the official technical disclosure.

Detection Methods for CVE-2026-20413

Indicators of Compromise

• Unexpected kernel panics or crash logs referencing the imgsys driver or image signal processor subsystems.
• Processes running with System privileges making unusual ioctl calls to imgsys device nodes.
• Android logcat entries showing repeated failed access attempts against MediaTek camera or ISP drivers.

Detection Strategies

• Monitor Android security patch level on managed devices and flag endpoints lacking the February 2026 MediaTek patch.
• Inspect mobile device management (MDM) telemetry for installed applications requesting privileged camera or ISP access outside expected baselines.
• Correlate kernel crash dumps with imgsys-related stack frames as a signal of attempted or successful exploitation.

Monitoring Recommendations

• Enforce mobile threat defense policies that block sideloaded applications and unverified APK installations on MediaTek-based devices.
• Track MediaTek and Google Android Security Bulletin releases and validate patch propagation by OEMs to deployed fleets.
• Audit privileged application inventory on affected MT6899, MT6991, MT8678, and MT8793 devices for anomalous behavior.

How to Mitigate CVE-2026-20413

Immediate Actions Required

• Apply the MediaTek patch ALPS10362725 referenced in Issue ID MSV-5694 as soon as OEM firmware updates become available.
• Update affected Android 15.0 devices to the February 2026 security patch level or later through OEM-provided OTA updates.
• Restrict installation of untrusted applications on devices using MT6899, MT6991, MT8678, or MT8793 chipsets.

Patch Information

MediaTek addressed the vulnerability in the MediaTek Security Bulletin February 2026. The fix is delivered through device OEM firmware updates incorporating MediaTek Patch ID ALPS10362725. Device administrators should verify the Android security patch level reflects February 2026 or later on all managed endpoints.

Workarounds

• No vendor-supplied workaround exists; patching through OEM firmware updates is the only complete remediation.
• Reduce the attack surface by limiting which applications can request System-level privileges through enterprise mobility management policies.
• Disable or remove non-essential privileged third-party applications on affected MediaTek devices until patches are deployed.