Description

Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-18T13:17:30.513Z",
  "pubdate": "2026-08-18T13:17:30.513Z",
  "executiveSummary": "A privilege escalation vulnerability exists within the Graphics: CanvasWebGL component of the Mozilla Firefox browser. This security flaw allows malicious entities to execute unauthorized actions with elevated privileges within the context of the application. The vulnerability impacts specific versions of Mozilla Firefox and Firefox ESR, specifically prior to the implementation of the vendor patches. Successful exploitation of this flaw can compromise the security boundaries of the browser engine, potentially leading to arbitrary code execution or sandbox escape depending on the attacker's initial positioning and execution chain. Risk implications involve the complete compromise of browser-managed sessions and host system integration if chained with additional remote code execution or memory corruption primitives. Attacker capabilities typically require tricking a user into navigating to a malicious web page designed to trigger the CanvasWebGL processing flaw. No explicit authentication or prior specialized privileges are required beyond standard web content interaction, though successful exploitation relies on triggering specific vulnerable code paths within the rendering pipeline.",
  "technicalDetails": "The vulnerability resides within the Graphics: CanvasWebGL component of Mozilla Firefox, which handles WebGL rendering contexts and underlying graphics operations for HTML5 canvas elements. The root cause stems from improper handling of state management, memory allocation, or type confusion within the WebGL processing engine, leading to memory safety violations or logic flaws when rendering specialized graphics commands.\nExploitation occurs when a maliciously crafted web page interacts with the CanvasWebGL API, supplying specially formatted shaders, buffers, or texture parameters that trigger the underlying flaw. The attack flow begins as the browser parses the malicious web content and instantiates a WebGL context via the vulnerable component. Due to inadequate input validation or improper bounds checking within the graphics pipeline, malformed data manipulation leads to corrupted memory states or unauthorized access to privileged interfaces.\nThe vulnerable component is explicitly the Graphics: CanvasWebGL subsystem. Affected versions include Mozilla Firefox prior to version 154, Firefox ESR prior to version 140.14, and Firefox ESR prior to version 153.1. Network exposure is present whenever a user visits an untrusted website hosting the exploit payload, as web content is processed automatically by the browser rendering engine. No authentication or elevated user privileges are required to initiate the attack vector.\nThe payload behavior leverages the resulting memory corruption or logic flaw to elevate privileges within the execution environment of the browser process. Post-exploitation impact can range from arbitrary code execution within the content process to sandbox breakout scenarios, enabling the adversary to interact with the underlying operating system under the security context of the user running the browser application."
}