MediaWiki Improper Neutralization of Input During Web Page Generation (Cross-site Scripting) Vulnerability - CVE-2014-2242
includes/upload/UploadBase.php in MediaWiki before 1.19.12 1.20.x and 1.21.x before 1.21.6 and 1.22.x before 1.22.3 does not prevent use of invalid namespaces in SVG files which allows remote attackers to conduct cross-site scripting (XSS) attacks via an SVG upload as demonstrated by use of a W3C XHTML namespace in conjunction with an IFRAME element.