Description

Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 157.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-09-29T13:17:41.043Z",
  "pubdate": "2026-09-29T13:17:41.043Z",
  "executiveSummary": "A critical Use-After-Free (UAF) vulnerability has been identified within the WebGPU component of the Firefox browser, specifically resolved in version 157. This vulnerability type occurs when the application continues to use a memory pointer after the memory it references has been deallocated.\nThe flaw affects the Graphics subsystem, posing a severe risk to end-users. Successful exploitation allows a remote attacker to achieve arbitrary code execution within the context of the browser process. By leveraging memory corruption, an adversary can potentially bypass security sandbox protections, leading to full system compromise.\nThe vulnerability requires the victim to interact with malicious web content, such as a specially crafted website utilizing the WebGPU API. Given the nature of UAF vulnerabilities, the exploit flow involves heap manipulation to gain control over the instruction pointer or to influence browser object states.\nThe risk implication is high, as it facilitates memory manipulation without requiring prior authentication. Organizations and users are advised to update to Firefox 157 or later to remediate the underlying memory safety issue.",
  "technicalDetails": "The vulnerability originates in the WebGPU implementation within the Firefox Graphics component. Use-After-Free (UAF) conditions in complex browser rendering engines typically arise when the lifecycle management of GPU-bound objects is improperly synchronized between the main thread and the GPU process.\nThe attack flow begins when an attacker triggers a specific sequence of WebGPU API calls, such as resource creation, binding, and deletion, to induce a race condition or a lifecycle logic error. Once a memory object is freed but remains referenced by a dangling pointer within the WebGPU state tracking structure, the attacker performs heap spraying to occupy the newly freed memory region with attacker-controlled data.\nBecause WebGPU relies on low-level memory management to handle heavy computational and graphical tasks, the UAF vulnerability allows for the corruption of internal vtable pointers or callback structures. By overwriting these pointers, the attacker can redirect the browser's execution flow when the dangling pointer is subsequently dereferenced.\nExploitation typically necessitates a multi-stage process: first, the attacker must achieve memory stability to reliably allocate malicious objects into the specific heap location vacated by the freed WebGPU object. Second, the attacker must trigger the dereference of the stale pointer, which executes the injected payload or redirects execution to a ROP (Return-Oriented Programming) chain.\nThis vulnerability is particularly dangerous because it bypasses standard JavaScript sandbox restrictions. Once code execution is achieved in the rendering process, the attacker may attempt to escape the sandbox to gain native execution capabilities on the host operating system. The vulnerability exists within the Firefox engine and impacts all versions prior to 157. Authentication is not required, as the vector is network-based through standard browser content delivery mechanisms."
}