Heap Buffer Overflow in NVIDIA CUDA Driver User Mode API Allows for Privilege Escalation and Denial of Service
Overview
NVIDIA released a security bulletin addressing a high-severity vulnerability in the user-mode layer of its CUDA driver for Linux systems. The vulnerability, identified as CVE-2026-11842, is a heap-based buffer overflow that can be triggered by a specially crafted CUDA kernel. A local attacker with basic user permissions can exploit this flaw by running a malicious application that utilizes the CUDA API. When the driver attempts to process the malformed kernel, it incorrectly calculates the size of a buffer required for an operation, leading to a write of data beyond the allocated heap memory boundary. This memory corruption can lead to two primary impacts. The most likely outcome is a crash of the user-mode driver, resulting in a denial of service (DoS) for all applications relying on the GPU for computation or rendering, and potentially causing a full system crash (kernel panic) due to the unstable state. More critically, sophisticated attackers could potentially leverage the heap overflow to control the overwritten memory and achieve arbitrary code execution within the context of the driver process. If the driver process runs with elevated privileges (e.g., as part of the `root` user's display server), this could lead to a full local privilege escalation, allowing the attacker to gain complete control over the system. The vulnerability affects a wide range of enterprise and consumer GPU drivers on Linux platforms.
Affected Systems
Testing Guide
1. **Check Current Driver Version:** Open a terminal and run the command `nvidia-smi`. 2. **Inspect Driver Version:** The output will display the installed NVIDIA driver version in the top right corner. 3. **Compare with Patched Versions:** Cross-reference your installed version with the patched versions listed in the official NVIDIA Security Bulletin. If your version is lower than the fixed versions, you are affected and should update immediately.
Mitigation Steps
1. **Update NVIDIA Drivers:** Download and install the latest version of the NVIDIA driver from the official NVIDIA website or your Linux distribution's package manager. 2. **Limit User Access:** On multi-user systems, restrict access to GPU resources to only trusted users to prevent a low-privilege user from exploiting the vulnerability. 3. **Monitor System Logs:** Keep an eye on kernel and system logs for any signs of driver crashes or instability, which could indicate attempted exploitation.
Patch Details
Patched in NVIDIA driver versions 550.90.07, 545.29.06, 535.104.05 and newer.