Cross-site scripting (XSS) vulnerability in the TimeMediaHandler extension for MediaWiki before 1.19.10, 1.2x before 1.21.4, and 1.22.x before 1.22.1 allows remote attackers to inject arbitrary web script or HTML via vectors related to videos.
http://lists.wikimedia.org/pipermail/mediawiki-announce/2014-January/000138.html