CVE-2026-100799 in Firefox
Summary
by MITRE • 09/29/2026
Uninitialized memory in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 157.
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Analysis
by VulDB Data Team • 09/29/2026
The identified security issue resides within the Graphics subsystem of Mozilla Firefox, specifically affecting the implementation of the WebGPU API. Uninitialized memory vulnerabilities represent a class of defects where software accesses memory locations that have not been properly initialized with valid data prior to use. In the context of browser-based graphics processing units and shader execution environments like WebGPU, such flaws can arise when internal buffers or state variables are allocated but left in an indeterminate state before being read by rendering pipelines or compute shaders. This lack of initialization means that the application may inadvertently utilize residual data from previous operations or random memory contents, leading to unpredictable behavior during graphical computation tasks.
From a technical perspective, this flaw aligns with CWE-457, which describes the use of an uninitialized variable. When the WebGPU component processes complex rendering commands or shader programs, it relies on precise state management for texture sampling, buffer binding, and pipeline configuration. If specific internal structures are not zeroed out or explicitly set before being passed to lower-level graphics drivers or executed within the GPU context, the resulting operations may produce corrupted visual artifacts, crashes, or potentially allow an attacker to infer sensitive information from adjacent memory regions if the uninitialized data overlaps with other security-sensitive contexts. While primarily a stability and correctness issue in most scenarios, improper handling of such memory states can sometimes be leveraged for more severe exploits depending on how the browser isolates web content and manages sandbox boundaries.
The operational impact of this vulnerability is significant due to its potential to destabilize the browsing session or compromise data integrity during intensive graphical tasks. Users engaging with WebGPU-accelerated applications, including 3D modeling tools, complex visualizations, or high-performance games running in Firefox, may experience application hangs, crashes, or rendering errors. For threat actors, such vulnerabilities can serve as a foothold for further exploitation if combined with other weaknesses, potentially leading to arbitrary code execution or information disclosure through side-channel attacks that exploit the non-deterministic nature of uninitialized memory reads. The vulnerability was addressed in Firefox version 157 by ensuring that all relevant internal structures are properly initialized before being utilized within the WebGPU rendering pipeline, thereby eliminating the source of undefined behavior and reinforcing the robustness of the graphics abstraction layer.
Mitigation strategies primarily involve relying on vendor patches to resolve these low-level memory management issues. Users should ensure their browsers are updated to version 157 or later to benefit from the fix for this uninitialized memory flaw. Additionally, developers utilizing WebGPU in web applications can mitigate risks by adhering strictly to API specifications and validating all buffer states before submission to the GPU queue. From a defensive security standpoint, employing browser hardening techniques such as disabling unnecessary plugins that might interact with graphics APIs and keeping operating system drivers up to date helps reduce the attack surface associated with complex software stacks like browsers. This incident underscores the importance of rigorous memory safety practices in high-performance computing components within web browsers, aligning with broader industry efforts to secure critical infrastructure against subtle implementation errors that can lead to significant security compromises as documented in various ATT&CK techniques related to exploitation for privilege escalation or data exfiltration via unstable software states.