Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level advertisement and internet tracker blocking application. Pi-hole Admin Interface versions prior to 6.3 are vulnerable to cross-site scripting (XSS) via the Address field in the Subscribed Lists group management section. An authenticated user can inject malicious JavaScript by adding a payload to the Address field when creating or editing a list entry. The vulnerability is triggered when another user navigates to the Tools section and performs a gravity database update. The Address field does not properly sanitize input, allowing special characters and script tags to bypass validation. This has been patched in version 6.3.