CVE-2025-13019 is a vulnerability in Mozilla Firefox's DOM Workers component that enables bypassing the same-origin policy, a fundamental browser security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. This flaw could allow an attacker to access or manipulate data across origins improperly. The vulnerability was addressed and fixed in Firefox 145 and Firefox ESR 140.5 as per Mozilla's security advisories MFSA 2025-87 and MFSA 2025-88. The CVSS v3.1 base score is 8.1, reflecting network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, and high impact on confidentiality and integrity.

Successful exploitation of this vulnerability could allow an attacker to bypass the same-origin policy in Firefox, potentially leading to unauthorized access to sensitive information or manipulation of data across different web origins. The impact affects confidentiality and integrity but does not affect availability. No known active exploits have been reported in the wild at this time.

Mozilla has released official fixes for this vulnerability in Firefox 145 and Firefox ESR 140.5. Users and administrators should update affected Firefox installations to these versions or later to remediate the vulnerability. Since this is not a cloud service, remediation depends on applying these updates. Patch status is confirmed by the vendor advisories MFSA 2025-87 and MFSA 2025-88.