CVE-2026-20413: Google Android Privilege Escalation Flaw

CVE-2026-20413 Overview

CVE-2026-20413 is an out-of-bounds write vulnerability discovered in the MediaTek image processing subsystem (imgsys) affecting multiple MediaTek chipsets and Google Android 15.0 devices. The vulnerability stems from a missing bounds check that could allow an attacker who has already obtained System privileges to achieve local privilege escalation without requiring user interaction.

This vulnerability affects the image processing component used in various MediaTek System-on-Chip (SoC) solutions, which are widely deployed in Android smartphones, tablets, and other consumer devices.

Critical Impact

A privileged attacker with System-level access can exploit this out-of-bounds write to escalate privileges further, potentially gaining kernel-level control over affected Android devices running MediaTek chipsets.

Affected Products

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

Discovery Timeline

• 2026-02-02 - CVE-2026-20413 published to NVD
• 2026-02-03 - Last updated in NVD database

Technical Details for CVE-2026-20413

Vulnerability Analysis

The vulnerability exists within MediaTek's imgsys component, which handles image processing operations on affected chipsets. The root cause is a missing bounds check that allows memory writes beyond the intended buffer boundaries.

To successfully exploit this vulnerability, an attacker must first obtain System privileges on the target device. Once this prerequisite is met, the out-of-bounds write can be leveraged to corrupt adjacent memory regions, potentially allowing the attacker to escalate privileges to kernel level or execute arbitrary code with elevated permissions.

The attack requires local access to the device and does not need any user interaction, making it particularly concerning in scenarios where an attacker has already established a foothold on the system through another vulnerability or malicious application.

Root Cause

The vulnerability is caused by improper validation of input parameters or buffer sizes in the imgsys image processing subsystem. The code fails to perform adequate bounds checking before writing data to memory buffers, which corresponds to CWE-787 (Out-of-bounds Write) and CWE-1285 (Improper Validation of Specified Index, Position, or Offset in Input).

When the imgsys driver processes certain image data or commands, it does not properly verify that the write operations stay within the allocated buffer boundaries. This allows an attacker with System privileges to craft malicious inputs that trigger writes to memory locations outside the intended buffer.

Attack Vector

The attack vector for CVE-2026-20413 is local, requiring the attacker to have existing System-level privileges on the target Android device. The exploitation flow typically involves:

1. The attacker gains System privileges through another vulnerability or malicious application
2. The attacker interacts with the imgsys driver through device-specific interfaces or IOCTL calls
3. Maliciously crafted data is passed to the driver that triggers the out-of-bounds write condition
4. The attacker leverages the memory corruption to escalate privileges further or achieve arbitrary code execution

The vulnerability mechanism involves improper bounds validation in the MediaTek imgsys driver. When processing image-related operations, the driver accepts parameters that specify memory offsets or sizes without proper validation. An attacker with System privileges can provide carefully crafted values that cause the driver to write data beyond allocated buffer boundaries, corrupting adjacent kernel memory structures. For detailed technical information, refer to the MediaTek Security Bulletin February 2026.

Detection Methods for CVE-2026-20413

Indicators of Compromise

• Unexpected crashes or kernel panics in the imgsys driver or image processing subsystem
• Anomalous memory access patterns detected in kernel logs related to MediaTek drivers
• Suspicious privilege escalation events from System to kernel level on affected devices
• Unusual activity involving the MediaTek image processing driver interfaces

Detection Strategies

• Monitor Android system logs for abnormal imgsys driver behavior or error messages
• Implement runtime integrity checks for critical kernel memory regions
• Deploy mobile threat detection solutions capable of identifying privilege escalation attempts
• Use Android security audit tools to detect unauthorized access to hardware abstraction layer components

Monitoring Recommendations

• Enable verbose logging for MediaTek driver subsystems during security investigations
• Implement SentinelOne Singularity Mobile to detect exploitation attempts and anomalous behavior
• Regularly audit device firmware versions against known vulnerable configurations
• Monitor for applications requesting or abusing System-level privileges

How to Mitigate CVE-2026-20413

Immediate Actions Required

• Apply the latest Android security updates from device manufacturers that include patch ALPS10362725
• Verify device firmware is updated to versions that address MSV-5694
• Audit applications with System-level privileges and remove untrusted or unnecessary applications
• Implement mobile device management (MDM) policies to enforce timely security updates

Patch Information

MediaTek has released a security patch identified as ALPS10362725 to address this vulnerability. The patch adds proper bounds checking to the imgsys driver to prevent out-of-bounds write conditions. Device manufacturers should integrate this patch into their firmware updates, and users should apply the latest Android security patches as they become available.

For detailed patch information, refer to the MediaTek Security Bulletin February 2026.

Workarounds

• Limit the installation of applications to trusted sources only (Google Play Store or enterprise app stores)
• Disable or restrict developer options and USB debugging on production devices
• Implement network segmentation to isolate potentially compromised mobile devices
• Use SentinelOne Singularity Mobile for real-time threat detection and response on affected devices

# Check Android security patch level on device
adb shell getprop ro.build.version.security_patch

# Verify MediaTek chipset information
adb shell cat /proc/cpuinfo | grep Hardware

# List installed applications with elevated permissions for audit
adb shell pm list packages -f