CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to version 0.31.0.0, the application fails to properly sanitize user-controlled input when adding Posts to navigation menus through the Menu Management functionality. Post-related data selected via the Posts section is stored server-side and rendered without proper output encoding. These stored values are later rendered unsafely within administrative dashboards and public-facing navigation menus, resulting in stored DOM-based cross-site scripting (XSS). This issue has been patched in version 0.31.0.0.