Executive brief
A security vulnerability in the Firefox web browser could allow an attacker to bypass certain built-in security protections. Firefox is a widely used web browser, and this flaw affects the component responsible for managing web page security and structure. If exploited, this could allow malicious websites to circumvent safety measures intended to protect user data and browsing sessions.
Technical details
A mitigation bypass vulnerability was identified in the DOM: Security component of Mozilla Firefox. The flaw allows for the circumvention of security mechanisms designed to protect the Document Object Model (DOM). While specific technical details regarding the root cause are restricted in the associated bug report (Bug 2031123), the vulnerability typically involves an attacker-controlled web page bypassing security constraints enforced by the browser's security engine. This issue is rated as low impact by Mozilla and was resolved in Firefox 151.
Affected products
- Mozilla Firefox < 151
Timeline
- 2026-05-19: advisory: Mozilla Foundation Security Advisory 2026-46 published.
- 2026-05-19: patched: Fixed in Firefox 151.