MediaWiki before 1.18.5, and 1.19.x before 1.19.2 allows remote attackers to bypass GlobalBlocking extension IP address blocking and create an account via unspecified vectors.
Improper Access Control vulnerability in Wikimedia Foundation Mediawiki - Scribunto Extension allows : Accessing Functionality Not Properly Constrained by Authorization.This issue affects Mediawiki - Scribunto Extension: from 1.39.X before 1.39.12, from 1.42.X before 1.42.7, from 1.43.X before 1.43.2.
An issue was discovered in the GrowthExperiments extension for MediaWiki through 1.39.3. Attackers might be able to see edits for which the username has been hidden, because there is no check for rev_deleted.
MediaWiki 1.27.x before 1.27.1 might allow remote attackers to bypass intended session access restrictions by leveraging a call to the UserGetRights function after Session::getAllowedUserRights.
ApiParse in MediaWiki before 1.23.15, 1.26.x before 1.26.4, and 1.27.x before 1.27.1 allows remote attackers to bypass intended per-title read restrictions via a parse action to api.php.
MediaWiki before 1.23.12, 1.24.x before 1.24.5, 1.25.x before 1.25.4, and 1.26.x before 1.26.1 do not properly normalize IP addresses containing zero-padded octets, which might allow remote attackers to bypass intended access restrictions by using an IP address that was not supposed to have been allowed.
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.
MediaWiki before 1.23.15, 1.26.x before 1.26.4, and 1.27.x before 1.27.1 allows remote authenticated users with undelete permissions to bypass intended suppressrevision and deleterevision restrictions and remove the revision deletion status of arbitrary file revisions by using Special:Undelete.
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.