Executive brief
A security vulnerability has been identified in the networking component of the Firefox web browser. This flaw allows an attacker to bypass built-in security mitigations designed to protect users while they browse the web. If exploited, this could weaken the browser's defense-in-depth strategy, potentially making it easier for other vulnerabilities to be used against the user.
Technical details
A mitigation bypass vulnerability exists in the DOM: Networking component of Mozilla Firefox. The flaw allows for the circumvention of security protections, though specific details regarding the mechanism of the bypass are restricted in the associated bug reports (Bug 2041902). An attacker could potentially leverage this bypass to facilitate more complex attacks or weaken the browser's security posture. The vulnerability is addressed in Firefox 153 and Firefox ESR 140.13.
Affected products
- Mozilla Firefox < 153
- Mozilla Firefox ESR < 140.13
Timeline
- 2026-07-21: disclosed
- 2026-07-21: patched