Cross-site scripting (XSS) vulnerability in Movable Type before 3.2 allows remote attackers to inject arbitrary web script or HTML via the (1) title, (2) category, (3) body, (4) extended body, and (5) excerpt form fields in new blog entries.
http://secunia.com/advisories/16899
http://archives.neohapsis.com/archives/fulldisclosure/2005-11/0091.html