Description

Uninitialized memory in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 157.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.3",
  "pubDate": "2026-09-29T13:17:45.287Z",
  "pubdate": "2026-09-29T13:17:45.287Z",
  "executiveSummary": "A critical security vulnerability involving uninitialized memory exists within the WebGPU component of the Firefox browser, specifically resolved in version 157. This flaw pertains to improper memory management during the initialization or allocation phases of graphical processing operations.\nThe vulnerability allows an attacker to potentially leverage uninitialized memory buffers, which may contain sensitive data residue from previous heap operations. By triggering this state through specifically crafted WebGPU commands, an attacker could achieve unauthorized information disclosure or influence the control flow of the application.\nThe vulnerability affects the core graphics engine, impacting the browser's sandbox integrity. While exploitation requirements typically involve a victim navigating to a malicious web page capable of invoking WebGPU API calls, the potential impact ranges from cross-origin data leakage to potentially aiding in broader browser exploitation chains.\nThe risk implication is significant due to the exposure of heap-resident data, which could include credentials, tokens, or memory layout pointers necessary for bypassing Address Space Layout Randomization (ASLR). Users are strongly advised to update to version 157 or later to remediate this memory safety flaw.",
  "technicalDetails": "The vulnerability resides within the WebGPU component of the Firefox browser, where memory allocations for GPU-related resources are handled. The root cause is a failure to properly zero-initialize or nullify memory segments allocated for GPU-bound data structures prior to their use by the graphics driver or hardware interface.\nWhen the WebGPU API allocates memory for buffers or textures, it occasionally fails to overwrite stale data remaining from previous allocations. This uninitialized memory may persist in the heap or GPU memory regions accessible by the web content process. Because WebGPU acts as a bridge between high-level JavaScript APIs and low-level graphics hardware acceleration, the mismanagement of these memory segments results in a leakage of sensitive information.\nThe attack flow commences when a malicious script executes within a web context, invoking specific WebGPU API primitives. By exhausting certain GPU resource pools or manipulating the allocation lifecycle through rapid buffer creation and destruction, an attacker can coerce the browser into serving uninitialized memory buffers. When the attacker's script then reads from these buffers, it receives the residual data left by the browser's internal processes.\nFrom an exploitation perspective, this information disclosure is highly potent. The residual data may contain pointers to internal C++ objects or memory addresses, which are instrumental for an attacker to calculate the base address of loaded modules and bypass ASLR defenses. Furthermore, if sensitive user information happens to be resident in the reclaimed memory, the attacker can extract it without requiring elevated privileges or user interaction beyond initial page navigation.\nThis vulnerability does not require authentication, as it is exposed through the standard WebGPU interface accessible to any web content. The primary component involved is the Firefox graphics stack, specifically the WebGPU implementation that interfaces with the underlying platform graphics API (e.g., Vulkan, Metal, or D3D). Affected versions include all iterations of Firefox prior to the version 157 release. The impact of successful exploitation is typically classified as an information disclosure, though it serves as a critical primitive in multi-stage exploitation scenarios designed to achieve arbitrary code execution by defeating memory isolation guarantees."
}