Description

Privilege escalation in the DOM: Networking 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": "2026-08-18T13:17:29.737Z",
  "pubdate": "2026-08-18T13:17:29.737Z",
  "executiveSummary": "A privilege escalation vulnerability has been identified within the Document Object Model (DOM) networking component of the affected Mozilla Firefox software ecosystem. This security defect introduces significant risk to system integrity and security boundaries by allowing unauthorized elevation of privileges within the application context. The vulnerability impacts multiple product versions, specifically Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. Successful exploitation of this flaw enables malicious actors to bypass established security controls and execute unauthorized actions with elevated privileges. The threat profile associated with this vulnerability indicates that an attacker capable of exploiting the DOM networking subsystem can manipulate internal browser states, potentially leading to arbitrary code execution or unauthorized access to sensitive system resources depending on the specific execution context. Exploitation requirements typically involve interacting with malicious or compromised web content designed to trigger the flaw in the networking and DOM integration layers. Remediation requires immediate deployment of official vendor patches to neutralize the underlying architectural weakness.",
  "technicalDetails": "The vulnerability resides within the Document Object Model (DOM) and networking subsystem integration of the Mozilla Firefox browser. The root cause stems from improper handling of state transitions, memory management, or object references between the DOM API and underlying networking components. Specifically, flaws in this boundary often manifest as type confusion, use-after-free conditions, or improper validation of cross-origin or cross-context messages passing through networking handlers exposed to the DOM.\nThe attack flow initiates when a targeted user navigates to a maliciously crafted webpage or is exposed to malicious web content controlled by an adversary. The attacker leverages specially crafted scripts that interact with vulnerable DOM networking APIs to trigger improper memory manipulation or logic bypasses. Because the networking component interacts closely with core browser privileges, manipulating these interfaces can allow malicious JavaScript or untrusted execution contexts to escalate their privilege level within the browser sandbox or underlying OS process.\nRegarding execution constraints, the vulnerability does not explicitly mandate pre-existing authentication, as it can be triggered remotely via untrusted web content processed by the browser. However, successful exploitation relies on the victim interacting with the malicious payload, such as visiting a compromised URL. The privilege requirements prior to exploitation are minimal, assuming standard unprivileged browser execution, while the post-exploitation impact includes potential arbitrary code execution, sandbox escape, or unauthorized access to sensitive local data structures accessible via the browser process."
}