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 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 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 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 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 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 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 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 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 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. SportsTeams: Special:SportsManagerLogo and Special:SportsTeamsManagerLogo do not check for the sportsteamsmanager user right, and thus an attacker may be able to affect pages that are concerned with sports teams.