Cross-site scripting (XSS) vulnerability in thumb.php in MediaWiki before 1.23.10, 1.24.x before 1.24.3, and 1.25.x before 1.25.2 allows remote attackers to inject arbitrary web script or HTML via the rel404 parameter, which is not properly handled in an error page.
https://security.gentoo.org/glsa/201510-05
https://lists.wikimedia.org/pipermail/mediawiki-announce/2015-August/000179.html
http://www.securityfocus.com/bid/76334
http://www.openwall.com/lists/oss-security/2015/08/27/6
http://www.openwall.com/lists/oss-security/2015/08/12/6
http://lists.fedoraproject.org/pipermail/package-announce/2015-August/165193.html