CVE-2026-20425 Overview
CVE-2026-20425 is an out-of-bounds write vulnerability in the MediaTek display component affecting Android devices powered by a wide range of MediaTek chipsets. The flaw stems from a missing bounds check in display-related code, allowing memory corruption beyond an allocated buffer. An attacker who has already gained System privilege on the device can exploit this issue to escalate to higher kernel-level privileges without user interaction. MediaTek tracks the fix as Patch ID ALPS10320471 and Issue ID MSV-5539. The vulnerability is classified under [CWE-787: Out-of-bounds Write].
Critical Impact
Local privilege escalation from System to a higher privilege context on Android devices using affected MediaTek chipsets, with no user interaction required.
Affected Products
- Google Android 14.0, 15.0, and 16.0
- MediaTek chipsets: MT6739, MT6761, MT6765, MT6768, MT6781, MT6789, MT6833, MT6835, MT6853, MT6855, MT6877, MT6878, MT6879
- MediaTek chipsets: MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899, MT6983, MT6985, MT6989, MT6991, MT6993, MT8196, MT8678, MT8793
Discovery Timeline
- 2026-03-02 - CVE-2026-20425 published to the National Vulnerability Database
- March 2026 - MediaTek publishes fix in the MediaTek March 2026 Security Bulletin
- 2026-03-03 - Last updated in the NVD database
Technical Details for CVE-2026-20425
Vulnerability Analysis
The vulnerability resides in the MediaTek display driver component shipped on Android devices using the listed chipsets. A code path responsible for handling display buffers or descriptor structures performs a write operation without validating the destination index or size against the bounds of the target buffer. As a result, attacker-controlled data can be written past the end of an allocated region, corrupting adjacent kernel memory.
Because the affected component runs in a privileged context, successful exploitation translates memory corruption into privilege escalation. The attacker must already possess System privilege, meaning this issue is typically chained from another vulnerability granting initial code execution as the system user on Android. From that position, the bug provides a route into kernel or other higher-privileged contexts.
Root Cause
The root cause is a missing bounds check before a write into a kernel-side buffer in the display subsystem [CWE-787]. Input values that should be validated against the allocated size of the target structure are trusted, allowing out-of-bounds memory writes when crafted parameters are supplied through the driver's interface.
Attack Vector
The attack vector is local. A malicious application or process running with System privilege issues crafted requests to the vulnerable display driver interface. The driver performs an unchecked write, corrupting adjacent kernel memory. By shaping the corruption, the attacker overwrites function pointers or privilege-related structures to escalate to kernel-level execution. No user interaction is required, and exploitation does not produce visible artifacts to the device user. Refer to the MediaTek March 2026 Security Bulletin for vendor-confirmed technical details.
Detection Methods for CVE-2026-20425
Indicators of Compromise
- Unexpected crashes or kernel panics referencing the MediaTek display driver in dmesg or Android tombstone logs
- Processes running as system spawning unexpected child processes or transitioning to root/kernel-level contexts
- Installation of unsigned or sideloaded applications that request privileged display-related interfaces
Detection Strategies
- Monitor mobile fleet telemetry for Android builds missing the March 2026 MediaTek security patch level on affected chipsets
- Inspect application behavior for native code interacting with /dev/ nodes exposed by the MediaTek display driver from non-vendor processes
- Correlate SELinux denials and kernel oops events that reference display driver symbols across managed devices
Monitoring Recommendations
- Enforce monthly Android security patch level reporting through MDM/EMM for devices using MediaTek chipsets
- Alert on devices reporting a security patch level older than March 2026 on the affected models
- Track installation of applications requesting low-level graphics or display permissions, especially on enrolled corporate devices
How to Mitigate CVE-2026-20425
Immediate Actions Required
- Apply the March 2026 Android security patch level on all affected MediaTek-based devices as soon as the OEM build is available
- Identify fleet devices using the listed MediaTek chipsets and prioritize patch rollout through your MDM/EMM platform
- Restrict installation of untrusted applications on affected devices until patches are deployed
Patch Information
MediaTek has released a fix tracked as Patch ID ALPS10320471 (Issue ID MSV-5539), documented in the MediaTek March 2026 Security Bulletin. The fix introduces the missing bounds check in the display component. OEMs integrate this patch into their Android security patch level updates; users should install the latest update offered by their device manufacturer.
Workarounds
- No vendor-supplied workaround exists; applying the OEM firmware update is the only complete remediation
- Limit the device to managed app stores and block sideloading via MDM policy to reduce the likelihood of an attacker first achieving System privilege
- Enforce Android Verified Boot and ensure SELinux remains in enforcing mode to constrain pre-conditions required for exploitation
# Verify the Android security patch level on a connected device
adb shell getprop ro.build.version.security_patch
# Expected output for remediated devices: 2026-03-01 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
