Cross-site scripting (XSS) vulnerability in MediaWiki before 1.16.4, 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 .html located before a ? (question mark) in a 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.

The transwiki import functionality in MediaWiki before 1.16.3 does not properly check privileges, which allows remote authenticated users to perform imports from any wgImportSources wiki via a crafted POST request.

The checkCss function in includes/Sanitizer.php in the wikitext parser in MediaWiki before 1.16.3 does not properly validate Cascading Style Sheets (CSS) token sequences, which allows remote attackers to conduct cross-site scripting (XSS) attacks or obtain sensitive information by using the \2f\2a and \2a\2f hex strings to surround CSS comments.

Multiple directory traversal vulnerabilities in (1) languages/Language.php and (2) includes/StubObject.php in MediaWiki 1.8.0 and other versions before 1.16.2, when running on Windows and possibly Novell Netware, allow remote attackers to include and execute arbitrary local PHP files via vectors related to a crafted language file and the Language::factory function.

Cross-site scripting (XSS) vulnerability in MediaWiki before 1.16.2 allows remote attackers to inject arbitrary web script or HTML via crafted Cascading Style Sheets (CSS) comments, aka "CSS injection vulnerability."

MediaWiki before 1.16.1, when user or site JavaScript or CSS is enabled, allows remote attackers to conduct clickjacking attacks via unspecified vectors.

MediaWiki before 1.15.3, and 1.6.x before 1.16.0beta2, does not properly handle a correctly authenticated but unintended login attempt, which makes it easier for remote authenticated users to conduct phishing attacks by arranging for a victim to login to the attacker's account and then execute a crafted user script, related to a "login CSRF" issue.