Cross-site scripting (XSS) vulnerability in MediaWiki before 1.16.5, when Internet Explorer 6 or earlier is used, allows remote attackers to inject arbitrary web script or HTML via an uploaded file accessed with a dangerous extension such as .shtml at the end of the query string, in conjunction with a modified URI path that has a %2E sequence in place of the . (dot) character. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-1578 and CVE-2011-1587.
https://bugzilla.redhat.com/show_bug.cgi?id=702512
http://www.securityfocus.com/bid/47722
http://secunia.com/advisories/44684
http://lists.wikimedia.org/pipermail/mediawiki-announce/2011-May/000098.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-May/060507.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-May/060496.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-May/060435.html