CVE-2026-21732 in Graphics DDK
Summary
by MITRE • 03/21/2026
A web page that contains unusual GPU shader code is loaded into the GPU compiler process and can trigger a write out-of-bounds write crash in the GPU shader compiler library. On certain platforms, when the compiler process has system privileges this could enable further exploits on the device.
An edge case using a very large value in switch statements in GPU shader code can cause a segmentation fault in the GPU shader compiler due to an out-of-bounds write access.
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Analysis
by VulDB Data Team • 03/27/2026
This vulnerability represents a critical security flaw in GPU shader compiler implementations that can lead to privilege escalation and system compromise. The issue manifests when malformed GPU shader code containing unusual or excessively large values in switch statements is processed by the GPU compiler component. The vulnerability specifically targets the compilation phase where shader code is translated into executable GPU instructions, creating a dangerous condition that can be exploited by malicious actors.
The technical root cause involves an out-of-bounds write operation within the GPU shader compiler library that occurs when processing switch statements with extremely large values. This type of vulnerability falls under the CWE-787 Out-of-bounds Write classification, where the compiler fails to properly validate input parameters before writing to memory locations. The flaw exists in the bounds checking mechanisms of the shader compiler, which do not adequately handle edge cases involving massive switch statement values that exceed normal computational expectations.
When the GPU compiler processes such malformed shader code, it attempts to allocate memory or update internal data structures based on the invalid switch value, resulting in a segmentation fault that manifests as a write out-of-bounds crash. This crash typically occurs during the compilation phase before the shader code is executed, but the memory corruption can be exploited to gain control over the GPU compiler process. The vulnerability becomes particularly dangerous on platforms where the GPU compiler runs with elevated system privileges, as the compromised process can then be leveraged to execute arbitrary code with the same elevated permissions.
The operational impact of this vulnerability extends beyond simple denial of service scenarios. Attackers can potentially leverage the out-of-bounds write condition to craft malicious shader code that, when loaded by a vulnerable application, triggers the memory corruption and enables privilege escalation. This aligns with ATT&CK technique T1068 for bypassing system protections and potentially T1547 for privilege escalation through process manipulation. The vulnerability affects systems where GPU shaders are compiled dynamically, particularly in web browsers, graphics applications, or any software that processes third-party shader code.
Mitigation strategies should focus on input validation and bounds checking within the GPU compiler components, ensuring that switch statement values are properly constrained and validated before processing. Organizations should implement sandboxing mechanisms for GPU compiler processes and maintain strict privilege separation between user applications and system-level compiler components. Additionally, regular updates and patches should be applied to GPU driver software and graphics libraries that contain the affected compiler implementations. The vulnerability demonstrates the importance of comprehensive testing for edge cases in graphics processing pipelines and highlights the need for robust memory safety mechanisms in GPU compiler architectures.