ChurchCRM is an open-source church management system. Prior to version 6.0.0, the application stores user-supplied HTML/JS without sufficient sanitization/encoding. When other users later view this content, attacker-controlled JavaScript executes in their browser (stored XSS).

In affected contexts the script can access web origin data and perform privileged actions as the victim. Where session cookies are not marked HttpOnly, the script can read document.cookie, enabling session theft and account takeover. Version 6.0.0 patches the issue.