grav-plugin-admin is the admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.10.49.5, the application fails to properly validate and sanitize user input in the data[header][title] parameter. As a result, attackers can craft a malicious URL with an XSS payload. When this URL is accessed, the injected script is reflected back in the HTTP response and executed within the context of the victim's browser session. This vulnerability is fixed in 1.10.49.5.