Description

Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 154 and Firefox ESR 153.1.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.4",
  "pubDate": "2026-08-18T13:17:34.440Z",
  "pubdate": "2026-08-18T13:17:34.440Z",
  "executiveSummary": "A site isolation vulnerability has been identified within the Graphics component of Firefox, posing significant security risks to affected browser environments. This flaw undermines the core security boundary enforced by site isolation mechanisms, potentially allowing cross-origin data exposure or unauthorized resource access under specific conditions. The vulnerability affects Firefox up to version 154 and Firefox ESR up to version 153.1.\nThe risk implications involve the potential bypass of security controls designed to isolate processes and memory spaces between distinct web origins. An attacker capable of exploiting this vulnerability could leverage compromised rendering logic within the graphics subsystem to interact with sensitive cross-origin data. Successful exploitation generally requires an attacker to lure a user into loading a maliciously crafted web page or exploiting a secondary context within the browser's rendering pipeline. Remediation requires updating the affected software to the patched versions where the underlying architectural enforcement within the Graphics component has been corrected.",
  "technicalDetails": "The vulnerability resides within the Graphics component of Firefox, specifically concerning the implementation and enforcement of site isolation boundaries. Site isolation is a security architecture engineered to put web sites from different origins into separate operating system processes, thereby preventing side-channel attacks and unauthorized cross-origin information disclosures. The root cause stems from a flaw in how the Graphics component handles cross-origin resource sharing, rendering pipelines, or memory buffers, allowing data boundaries to be traversed or improperly validated.\nDuring standard operation, the browser relies on strict process separation to ensure that content scripts, rendering engines, and graphics processing units operate within constrained security contexts. In this vulnerable state, an attacker can manipulate graphics-related operations—such as texture allocation, canvas manipulation, or accelerated rendering commands—to interact with memory spaces or resources belonging to a different origin. The attack flow typically begins when a user navigates to a malicious web page controlled by the attacker. The malicious content triggers specific sequences of graphics rendering instructions designed to exploit the logic flaw in the Graphics component.\nBecause the component fails to properly validate or isolate the origin context associated with the graphical operations, the boundary enforcement mechanisms are bypassed. This enables unauthorized read or write primitives depending on the exact nature of the memory handling flaw. The vulnerability affects Firefox prior to version 154 and Firefox ESR prior to version 153.1. Authentication and elevated privileges are not required for initial exploitation, as the attack vector is exposed via standard web content processing through network exposure of the browser engine. Post-exploitation impact could include the extraction of sensitive cross-origin data, persistent compromise of the rendering process, or further escalation within the browser's security sandbox architecture."
}