Cross-site scripting (XSS) vulnerability in templates/2k11/admin/entries.tpl in Serendipity before 2.0.1 allows remote authenticated editors to inject arbitrary web script or HTML via the serendipity[cat][name] parameter to serendipity_admin.php, when creating a new category.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.