An Incorrect Access Control vulnerability was found in Wikimedia MediaWiki 1.18.0 through 1.32.1. It is possible to bypass the limits on IP range blocks ($wgBlockCIDRLimit) by using the API. Fixed in 1.32.2, 1.31.2, 1.30.2 and 1.27.6.
MediaWiki through 1.32.1 has Incorrect Access Control (issue 1 of 3). A spammer can use Special:ChangeEmail to send out spam with no rate limiting or ability to block them. Fixed in 1.32.2, 1.31.2, 1.30.2 and 1.27.6.
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 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.