CVE-2025-13016 is a vulnerability caused by incorrect boundary conditions in the JavaScript WebAssembly component of Mozilla Firefox. This issue affects Firefox versions prior to 145 and Firefox ESR versions prior to 140.5. The vulnerability is classified under CWE-703 (Improper Check or Handling of Exceptional Conditions) and has a CVSS v3.1 base score of 7.5, indicating high severity. The flaw could potentially allow attackers to compromise memory safety, impacting confidentiality, integrity, and availability of the affected software. Mozilla addressed this vulnerability with an official fix released in Firefox 145 and Firefox ESR 140.5, as documented in their security advisories MFSA 2025-87 and MFSA 2025-88.

The vulnerability impacts the JavaScript WebAssembly component, leading to potential memory safety issues that could result in high impact on confidentiality, integrity, and availability of the affected Firefox and Thunderbird versions. Exploitation could allow arbitrary code execution or other severe consequences. However, no known exploits in the wild have been reported to date.

An official fix for CVE-2025-13016 is available and has been released 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 this vulnerability. No additional mitigation actions are required beyond applying the official patches.