Description

Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-18T13:17:30.233Z",
  "pubdate": "2026-08-18T13:17:30.233Z",
  "executiveSummary": "A privilege escalation vulnerability has been identified within the Document Object Model (DOM) Navigation component of Mozilla Firefox. This security flaw allows malicious actors to execute unauthorized operations or elevate privileges within the context of the browser engine by exploiting improper handling of navigation events and DOM manipulation.\nThe vulnerability directly impacts multiple versions of Firefox and Firefox Extended Support Release (ESR), specifically Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. Successful exploitation of this issue can lead to a compromise of browser security boundaries, potentially allowing attackers to bypass same-origin policy enforcement or execute arbitrary scripts with elevated privileges depending on the specific execution context.\nRisk implications include unauthorized access to sensitive application data, cross-site scripting (XSS) escalations, and potential system compromise if chained with other vulnerabilities. Attacker capabilities typically involve tricking a user into navigating to a malicious web page or interacting with specially crafted DOM elements designed to trigger the flaw. Exploitation requirements generally rely on browser interaction, lacking strict pre-existing authentication requirements against the target system, as the attack surface is exposed via standard web navigation mechanisms handled by the affected software.",
  "technicalDetails": "The vulnerability resides within the DOM Navigation component of the affected browser engine, where navigational state transitions and security context verifications are performed. The root cause stems from insufficient validation and sanitization of navigation parameters or improper enforcement of security boundaries during complex DOM manipulation sequences.\nVulnerable components include the internal navigation handlers and document object lifecycle management routines within Firefox. The affected software versions comprise Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. The flaw does not mandate prior authentication or administrative privilege requirements from the attacker's perspective, as network exposure is inherently tied to the browser's capability to process untrusted web content and remote URLs.\nThe step-by-step attack flow begins when an adversary crafts a malicious web page containing specialized scripts or DOM structures designed to manipulate the navigation state of the browser. When a user navigates to or interacts with this malicious content, the browser processes the crafted input through the flawed DOM Navigation component. Due to inadequate state validation or boundary checks, the navigation routine improperly transitions security contexts or leaks internal object references.\nThis behavior allows the payload to bypass intended isolation mechanisms, such as the same-origin policy, granting the attacker script execution capabilities within a higher privilege domain or the chrome context. Post-exploitation impact includes unauthorized reading of sensitive cross-origin data, manipulation of the browser DOM to spoof user interfaces, or execution of arbitrary code within the browser's execution environment, leading to a complete breakdown of browser-enforced security separation."
}