CVE-2026-20814
dxgkrnl.sys -- elevation of privilege in the DirectX Graphics Kernel
Summary
| Field | Value |
|---|---|
| Driver | dxgkrnl.sys (DirectX Graphics Kernel) |
| Vulnerability Class | Elevation of Privilege |
| CVSS | 7.8 |
| Exploited ITW | No |
| Patch Date | January 13, 2026 |
Context
The DirectX Graphics Kernel subsystem (dxgkrnl.sys) is the kernel-mode component of the Windows Display Driver Model (WDDM). It manages GPU scheduling, memory allocation, and the interface between user-mode graphics APIs and kernel-mode display miniport drivers. Every application that renders graphics, from browsers to games, communicates with dxgkrnl through DirectX system calls.
While dxgkrnl.sys has not been a frequent source of ITW exploits, it presents an enormous attack surface. The driver processes complex GPU resource management operations, handles shared surface allocations across processes, and manages virtual GPU memory mappings. The NVDrv technique documented in NVDrv demonstrates how GPU memory management interfaces can be leveraged for kernel read/write, and dxgkrnl sits at the heart of that subsystem.
Root Cause
Microsoft's advisory confirms a privilege escalation without disclosing the specific mechanism. DirectX Graphics Kernel vulnerabilities typically involve one of several patterns: incorrect handling of GPU resource sharing between processes, missing validation in GPU memory mapping operations, or race conditions in GPU command buffer processing. The kernel must arbitrate between multiple processes competing for GPU resources, and the synchronization and validation logic in this path is complex.
Exploitation
A local attacker sends crafted DirectX operations to trigger the vulnerability. DirectX system calls are reachable from any interactive session, and many of them do not require elevated privileges. The attacker leverages the EoP to gain SYSTEM privileges.
Exploitation Primitive
Crafted DirectX operation --> kernel vulnerability --> SYSTEM
Broader Significance
GPU subsystem vulnerabilities are an emerging area of kernel security research. The complexity of GPU resource management, combined with the fact that GPU drivers are among the largest kernel-mode components on any system, creates a substantial attack surface. As GPU computing becomes more prevalent (AI workloads, browser GPU acceleration), the dxgkrnl attack surface will only grow.