CVE-2026-20515: GPU Use After Free Vulnerability

CVE-2026-20515 Overview

CVE-2026-20515 is a use-after-free vulnerability [CWE-416] in the MediaTek GPU component. The flaw can trigger a system crash and enable local information disclosure. Exploitation requires low-privileged user execution and user interaction on the affected device. MediaTek tracks the fix under Patch ID ALPS11122991 and Issue ID MSV-8132, and addressed the vulnerability in the September 2026 MediaTek Security Bulletin.

Critical Impact
A local attacker with user-level privileges can crash affected devices and potentially disclose sensitive memory contents through GPU memory reuse after free.

Affected Products

MediaTek GPU driver component (see MediaTek Security Bulletin September 2026)
Devices integrating impacted MediaTek chipsets referenced by Patch ID ALPS11122991
Downstream OEM Android builds shipping the vulnerable GPU driver

Discovery Timeline

2026-09-07 - CVE-2026-20515 published to the National Vulnerability Database (NVD)
2026-09-08 - Last updated in the NVD database

Technical Details for CVE-2026-20515

Vulnerability Analysis

The vulnerability resides in the MediaTek GPU driver and is classified as a use-after-free condition [CWE-416]. The driver continues to reference memory after that memory has been freed, allowing the freed allocation to be reused for unrelated data. When the stale pointer is dereferenced, the driver can operate on attacker-influenced content or trigger memory corruption that crashes the system.

Because the flaw affects a kernel-mode GPU component, the reused allocation can hold sensitive kernel data. An attacker able to influence the reallocation window may read that data back through the GPU interface, leading to local information disclosure. MediaTek has issued a driver patch under ALPS11122991.

Root Cause

The root cause is improper lifetime management of a GPU memory object. Code paths in the driver retain or dereference a pointer to a buffer that has already been released to the allocator. Concurrent operations or crafted user requests can race with the free operation, leaving the driver with a dangling reference.

Attack Vector

The attack vector is local. An unprivileged application running on the device must invoke the affected GPU interface and requires user interaction to complete exploitation. Successful exploitation results in a system crash or disclosure of memory contents to the attacker-controlled process. Remote exploitation is not possible.

No public proof-of-concept exploit is available for CVE-2026-20515. Technical specifics are limited to the vendor advisory. See the MediaTek Security Bulletin September 2026 for authoritative details.

Detection Methods for CVE-2026-20515

Indicators of Compromise

Repeated GPU driver kernel panics or SIGSEGV events referencing the MediaTek GPU kernel module in dmesg or logcat.
Unexpected device reboots triggered by an unprivileged application invoking GPU ioctl interfaces.
Anomalous memory read patterns from user-space processes accessing GPU device nodes such as /dev/mali* or vendor-specific GPU nodes.

Detection Strategies

Monitor Android kernel logs for GPU driver faults correlated with a specific untrusted application UID.
Baseline normal GPU ioctl usage per application and alert on outliers that repeatedly exercise freed-object code paths.
Track application crash telemetry from Mobile Device Management (MDM) platforms for spikes in GPU-related faults after installation of new apps.

Monitoring Recommendations

Enforce collection of kernel crash reports from managed mobile fleets to identify exploitation attempts early.
Review app install telemetry for unsigned or sideloaded packages that request GPU-accelerated APIs shortly after installation.
Alert on repeated tombstone entries in /data/tombstones/ implicating the GPU kernel module.

How to Mitigate CVE-2026-20515

Immediate Actions Required

Apply the vendor firmware update containing MediaTek Patch ID ALPS11122991 as soon as it is delivered by the device OEM.
Restrict installation of untrusted applications on affected devices through enterprise MDM policy.
Prioritize patch rollout for devices used by high-value users where information disclosure is unacceptable.

Patch Information

MediaTek addressed CVE-2026-20515 in the September 2026 Security Bulletin. The fix is tracked under Patch ID ALPS11122991 and Issue ID MSV-8132. Device OEMs must integrate the patch into their monthly Android security updates. Refer to the MediaTek Security Bulletin September 2026 for the authoritative fix reference.

Workarounds

Limit device attack surface by removing non-essential applications that leverage GPU-accelerated APIs.
Enforce Google Play Protect and disable installation from unknown sources on managed Android devices.
Where patched firmware is not yet available, escalate with the device OEM for an expedited update timeline.

bash

# Verify Android security patch level on a managed device
adb shell getprop ro.build.version.security_patch

# Confirm the device vendor and model to map to the correct OEM patch
adb shell getprop ro.product.manufacturer
adb shell getprop ro.product.model