Mediawiki before 1.28.1 / 1.27.2 / 1.23.16 contains a flaw, allowing a sysops to undelete pages, although the page is protected against it.

The OAuth extension for MediaWiki improperly negotiates a new client token only over Special:OAuth/initiate, which allows attackers to bypass intended IP address access restrictions by making an API request with an existing token.

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 attribute injection attacks via glossary rules.

api.php in MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2 has a Reflected File Download vulnerability.

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 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 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."

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.