An issue was discovered in SecurePoll in the Growth extension in MediaWiki through 1.36.2. Simple polls allow users to create alerts by changing their User-Agent HTTP header and submitting a vote.

A denial-of-service issue was discovered in MediaWiki before 1.35.6, 1.36.x before 1.36.4, and 1.37.x before 1.37.2. When many files exist, requesting Special:NewFiles with actor as a condition can result in a very long running query.

An issue was discovered in MediaWiki before 1.35.6, 1.36.x before 1.36.4, and 1.37.x before 1.37.2. Users with the editinterface permission can trigger infinite recursion, because a bare local interwiki is mishandled for the mainpage message.

An issue was discovered in the MediaWiki through 1.38.2. The community configuration pages for the GrowthExperiments extension could cause a site to become unavailable due to insufficient validation when certain actions (including page moves) were performed.

An issue was discovered in MediaWiki before 1.37.3 and 1.38.x before 1.38.1. The contributions-title, used on Special:Contributions, is used as page title without escaping. Hence, in a non-default configuration where a username contains HTML entities, it won't be escaped.

An issue was discovered in MediaWiki before 1.35.7, 1.36.x and 1.37.x before 1.37.3, and 1.38.x before 1.38.1. XSS can occur in configurations that allow a JavaScript payload in a username. After account creation, when it sets the page title to "Welcome" followed by the username, the username is not escaped: SpecialCreateAccount::successfulAction() calls ::showSuccessPage() with a message as second parameter, and OutputPage::setPageTitle() uses text().

An issue was discovered in MediaWiki through 1.38.1. The lemma length of a Wikibase lexeme is currently capped at a thousand characters. Unfortunately, this length is not validated, allowing much larger lexemes to be created, which introduces various denial-of-service attack vectors within the Wikibase and WikibaseLexeme extensions. This is related to Special:NewLexeme and Special:NewProperty.

An issue was discovered in MediaWiki through 1.37.2. The SecurePoll extension allows a leak because sorting by timestamp is supported,

The Nimbus skin for MediaWiki through 1.37.2 (before 6f9c8fb868345701d9544a54d9752515aace39df) allows XSS in Advertise link messages.

The admin API module in the QuizGame extension for MediaWiki through 1.37.2 (before 665e33a68f6fa1167df99c0aa18ed0157cdf9f66) omits a check for the quizadmin user.

The FanBoxes extension for MediaWiki through 1.37.2 (before 027ffb0b9d6fe0d823810cf03f5b562a212162d4) allows Special:UserBoxes CSRF.

The SemanticDrilldown extension for MediaWiki through 1.37.2 (before e688bdba6434591b5dff689a45e4d53459954773) allows SQL injection with certain '-' and '_' constraints.

The Private Domains extension for MediaWiki through 1.37.2 (before 1ad65d4c1c199b375ea80988d99ab51ae068f766) allows CSRF for editing pages that store the extension's configuration. The attacker must trigger a POST request to Special:PrivateDomains.

An issue was discovered in Mediawiki through 1.37.1. The check for the override-antispoof permission in the AntiSpoof extension is incorrect.

An issue was discovered in MediaWiki through 1.37.1. ImportPlanValidator.php in the FileImporter extension mishandles the check for edit rights.

An issue was discovered in MediaWiki through 1.37.1. The CentralAuth extension mishandles a ttl issue for groups expiring in the future.

An XSS issue was discovered in MediaWiki before 1.35.6, 1.36.x before 1.36.4, and 1.37.x before 1.37.2. The widthheight, widthheightpage, and nbytes properties of messages are not escaped when used in galleries or Special:RevisionDelete.

MediaWiki before 1.23.16, 1.24.x through 1.27.x before 1.27.2, and 1.28.x before 1.28.1 allows remote attackers to discover the IP addresses of Wiki visitors via a style="background-image: attr(title url);" attack within a DIV element that has an attacker-controlled URL in the title attribute.

An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. Special:CheckUserLog allows CheckUser XSS because of date mishandling, as demonstrated by an XSS payload in MediaWiki:October.

An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. A denial of service (resource consumption) can be accomplished by searching for a very long key in a Language Name Search.