An issue was discovered in the Foreground skin for MediaWiki through 1.42.1. There is stored XSS via MediaWiki:Sidebar top-level menu entries.

An issue was discovered in the Nimbus skin for MediaWiki through 1.42.1. There is Stored XSS via MediaWiki:Nimbus-sidebar menu and submenu entries.

An issue was discovered in the ArticleRatings extension for MediaWiki through 1.42.1. Special:ChangeRating allows CSRF to alter data via a GET request.

An issue was discovered in the Tempo skin for MediaWiki through 1.42.1. There is stored XSS via MediaWiki:Sidebar top-level menu entries.

An issue was discovered in the MediaWikiChat extension for MediaWiki through 1.42.1. CSRF can occur in API modules.

An issue was discovered in the Metrolook skin for MediaWiki through 1.42.1. There is stored XSS via MediaWiki:Sidebar top-level menu entries.

An issue was discovered in the GuMaxDD skin for MediaWiki through 1.42.1. There is stored XSS via MediaWiki:Sidebar top-level menu entries.

An issue was discovered in the CheckUser extension for MediaWiki through 1.42.1. The API can expose suppressed information for log events. (The log_deleted attribute is not applied to entries.)

An issue was discovered in the CheckUser extension for MediaWiki through 1.42.1. The Special:Investigate feature can expose suppressed information for log events. (TimelineService does not support properly suppressing.)

An issue was discovered in the GlobalBlocking extension in MediaWiki before 1.40.2. For a Special:GlobalBlock?uselang=x-xss URI, i18n-based XSS can occur via the parentheses message. This affects subtitle links in buildSubtitleLinks.

An issue was discovered in the Phonos extension in MediaWiki before 1.40.2. PhonosButton.js allows i18n-based XSS via the phonos-purge-needed-error message.

An issue was discovered in the WatchAnalytics extension in MediaWiki before 1.40.2. XSS can occur via the Special:PageStatistics page parameter.

An issue was discovered in the PageTriage extension in MediaWiki before 1.35.14, 1.36.x through 1.39.x before 1.39.6, and 1.40.x before 1.40.2. XSS can occur via the rev-deleted-user, pagetriage-tags-quickfilter-label, pagetriage-triage, pagetriage-filter-date-range-format-placeholder, pagetriage-filter-date-range-to, pagetriage-filter-date-range-from, pagetriage-filter-date-range-heading, pagetriage-filter-set-button, or pagetriage-filter-reset-button message.

An issue was discovered in the Cargo extension in MediaWiki before 1.35.14, 1.36.x through 1.39.x before 1.39.6, and 1.40.x before 1.40.2. The Special:Drilldown page allows XSS via artist, album, and position parameters because of applied filter values in drilldown/CargoAppliedFilter.php.

An issue was discovered in the CheckUser extension in MediaWiki before 1.35.14, 1.36.x through 1.39.x before 1.39.6, and 1.40.x before 1.40.2. XSS can occur via message definitions. e.g., in SpecialCheckUserLog.

An issue was discovered in the CampaignEvents extension in MediaWiki before 1.35.14, 1.36.x through 1.39.x before 1.39.6, and 1.40.x before 1.40.2. The Special:EventDetails page allows XSS via the x-xss language setting for internationalization (i18n).

An issue was discovered in MediaWiki before 1.35.14, 1.36.x through 1.39.x before 1.39.6, and 1.40.x before 1.40.2. In includes/logging/RightsLogFormatter.php, group-*-member messages can result in XSS on Special:log/rights.

An issue was discovered in DifferenceEngine.php in MediaWiki before 1.35.12, 1.36.x through 1.39.x before 1.39.5, and 1.40.x before 1.40.1. diff-multi-sameuser (aka "X intermediate revisions by the same user not shown") ignores username suppression. This is an information leak.

An issue was discovered in MediaWiki before 1.35.12, 1.36.x through 1.39.x before 1.39.5, and 1.40.x before 1.40.1. There is XSS in youhavenewmessagesmanyusers and youhavenewmessages i18n messages. This is related to MediaWiki:Youhavenewmessagesfromusers.

An issue was discovered in the SportsTeams extension for MediaWiki before 1.35.12, 1.36.x through 1.39.x before 1.39.5, and 1.40.x before 1.40.1. It does not check for the anti-CSRF edit token in Special:SportsTeamsManager and Special:UpdateFavoriteTeams.