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 creating or editing blog posts. An attacker can inject a malicious JavaScript payload into blog post content, which is then stored server-side. This stored payload is later rendered unsafely in multiple application views without proper output encoding, leading to stored cross-site scripting (XSS). This issue has been patched in version 0.31.0.0.