CVE-2025-13013 is a mitigation bypass vulnerability affecting the DOM: Core & HTML component in Mozilla Firefox. This vulnerability could allow an attacker to bypass security mitigations designed to protect the browser's DOM processing, potentially leading to partial compromise of confidentiality and integrity. The issue was fixed in Firefox 145 and Firefox ESR 140.5. The CVSS 3.1 base score is 6.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N), indicating network attack vector, low attack complexity, no privileges required, user interaction required, scope changed, and low impact on confidentiality and integrity with no impact on availability. No exploits are known in the wild as of the advisory date.

The vulnerability allows a mitigation bypass in the DOM: Core & HTML component, which could lead to partial compromise of confidentiality and integrity of browser data when exploited. User interaction is required for exploitation, and the attack can be performed remotely over the network. There is no impact on availability. No known active exploitation has been reported.

Mozilla has released official fixes for this vulnerability in Firefox 145, Firefox ESR 140.5, Thunderbird 145, and Thunderbird 140.5. Users and administrators should update to these versions or later to remediate the vulnerability. Since the issue is fixed in these releases, no additional mitigation steps are required beyond applying the official updates.