An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. Special:Contributions can leak that a "hidden" user exists.
An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. Users can bypass intended restrictions on deleting pages in certain "fast double move" situations. MovePage::isValidMoveTarget() uses FOR UPDATE, but it's only called if Title::getArticleID() returns non-zero with no special flags. Next, MovePage::moveToInternal() will delete the page if getArticleID(READ_LATEST) is non-zero. Therefore, if the page is missing in the replica DB, isValidMove() will return true, and then moveToInternal() will unconditionally delete the page if it can be found in the master.
An issue was discovered in MediaWiki before 1.31.13 and 1.32.x through 1.35.x before 1.35.2. When using the MediaWiki API to "protect" a page, a user is currently able to protect to a higher level than they currently have permissions for.
An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. On Special:NewFiles, all the mediastatistics-header-* messages are output in HTML unescaped, leading to XSS.
An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. On ChangesList special pages such as Special:RecentChanges and Special:Watchlist, some of the rcfilters-filter-* label messages are output in HTML unescaped, leading to XSS.
An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. Blocked users are unable to use Special:ResetTokens. This has security relevance because a blocked user might have accidentally shared a token, or might know that a token has been compromised, and yet is not able to block any potential future use of the token by an unauthorized party.
An issue was discovered in the GlobalUsage extension for MediaWiki through 1.35.1. SpecialGlobalUsage.php calls WikiMap::makeForeignLink unsafely. The $page variable within the formatItem function was not being properly escaped, allowing for XSS under certain conditions.
An issue was discovered in the CasAuth extension for MediaWiki through 1.35.1. Due to improper username validation, it allowed user impersonation with trivial manipulations of certain characters within a given username. An ordinary user may be able to login as a "bureaucrat user" who has a similar username, as demonstrated by usernames that differ only in (1) bidirectional override symbols or (2) blank space.