ChurchCRM is an open-source church management system. Prior to 6.5.3, a stored Cross-Site Scripting (XSS) vulnerability in ChurchCRM's Note Editor allows authenticated users with note-adding permissions to execute arbitrary JavaScript code in the context of other users' browsers, including administrators. This can lead to session hijacking, privilege escalation, and unauthorized access to sensitive church member data. This vulnerability is fixed in 6.5.3.