MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2 has XSS when the $wgShowExceptionDetails setting is false and the browser sends non-standard URL escaping.
MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2, when a private wiki is configured, provides different error messages for failed login attempts depending on whether the username exists, which allows remote attackers to enumerate account names and conduct brute-force attacks via a series of requests.
The implementation of raw message parameter expansion in MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2 allows HTML mangling attacks.
MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2 allows remote attackers to inject > (greater than) characters via the id attribute of a headline.
The language converter in MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2 allows attackers to replace text inside tags via a rule definition followed by "a lot of junk."
The language converter in MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2 allows attribute injection attacks via glossary rules.
Cross-site scripting (XSS) vulnerability in MediaWiki before 1.18.5 and 1.19.x before 1.19.2 allows remote attackers to inject arbitrary web script or HTML via a File: link to a nonexistent image.
Multiple cross-site scripting (XSS) vulnerabilities in MediaWiki before 1.18.5 and 1.19.x before 1.19.2, when unspecified JavaScript gadgets are used, allow remote attackers to inject arbitrary web script or HTML via the userlang parameter to w/index.php.
MediaWiki before 1.18.5, and 1.19.x before 1.19.2 does not send a restrictive X-Frame-Options HTTP header, which allows remote attackers to conduct clickjacking attacks via an embedded API response in an IFRAME element.