In Drupal's 3rd party module search auto complete prior to versions 7.x-4.8 there is a Cross Site Scripting vulnerability. This Search Autocomplete module enables you to autocomplete textfield using data from your website (nodes, comments, etc.). The module doesn't sufficiently filter user-entered text among the autocompletion items leading to a Cross Site Scripting (XSS) vulnerability. This vulnerability can be exploited by any user allowed to create one of the autocompletion item, for instance, nodes, users, comments.