ChurchCRM is an open-source church management system. A privilege escalation vulnerability exists in ChurchCRM prior to version 6.5.3. An authenticated user with specific mid-level permissions ("Edit Records" and "Manage Properties and Classifications") can inject a persistent Cross-Site Scripting (XSS) payload into an administrator's profile. The payload executes when the administrator views their own profile page, allowing the attacker to hijack the administrator's session, perform administrative actions, and achieve a full account takeover. This vulnerability is a combination of two separate flaws: an Insecure Direct Object Reference (IDOR) that allows any user to view any other user's profile, and a Broken Access Control vulnerability that allows a user with general edit permissions to modify any other user's record properties. Version 6.5.3 fixes the issue.