CVE-2026-16349

A critical vulnerability in the Firefox and Thunderbird browsers allows attackers to bypass the same-origin policy through a flaw in the DOM navigation component, potentially leading to unauthorized access to sensitive data across different origins. Users of affected versions should prioritize updating to Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, or Thunderbird 153 and 140.13 to mitigate the risk of exploitation. Organizations relying on these applications should act swiftly to protect their environments from potential data breaches.