Cross-site request forgery (CSRF) vulnerability in the Special:ExpandedTemplates page in MediaWiki before 1.19.22, 1.20.x through 1.22.x before 1.22.14, and 1.23.x before 1.23.7, when $wgRawHTML is set to true, allows remote attackers to hijack the authentication of users with edit permissions for requests that cross-site scripting (XSS) attacks via the wpInput parameter, which is not properly handled in the preview.