CVE-2025-8031 is a vulnerability in Firefox and Thunderbird where the username:password portion of URLs was not properly stripped from Content Security Policy (CSP) reports. This flaw could lead to the unintended leakage of HTTP Basic Authentication credentials. The issue affects versions of Firefox prior to 141 and Thunderbird prior to 141, including certain ESR versions. Mozilla has addressed this vulnerability in Firefox 141 and Thunderbird 141.