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 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.

In MediaWiki through 1.37, the Special:ImportFile URI (aka FileImporter) allows XSS, as demonstrated by the clientUrl parameter.

In MediaWiki through 1.37, XSS can occur in Wikibase because an external identifier property can have a URL format that includes a $1 formatter substitution marker, and the javascript: URL scheme (among others) can be used.

In MediaWiki through 1.37, blocked IP addresses are allowed to edit EntitySchema items.

MediaWiki before 1.36.2 allows a denial of service (resource consumption because of lengthy query processing time). Visiting Special:Contributions can sometimes result in a long running SQL query because PoolCounter protection is mishandled.

MediaWiki before 1.36.2 allows a denial of service (resource consumption because of lengthy query processing time). ApiQueryBacklinks (action=query&list=backlinks) can cause a full table scan.

MediaWiki before 1.36.2 allows XSS. Month related MediaWiki messages are not escaped before being used on the Special:Search results page.

An issue was discovered in the Mentor dashboard in the GrowthExperiments extension in MediaWiki through 1.36.2. The Growthexperiments-mentor-dashboard-mentee-overview-add-filter-total-edits-headline, growthexperiments-mentor-dashboard-mentee-overview-add-filter-starred-headline, growthexperiments-mentor-dashboard-mentee-overview-info-text, growthexperiments-mentor-dashboard-mentee-overview-info-legend-headline, and growthexperiments-mentor-dashboard-mentee-overview-active-ago MediaWiki messages were not being properly sanitized and allowed for the injection and execution of HTML and JavaScript.

An issue was discovered in Special:MediaSearch in the MediaSearch extension in MediaWiki through 1.36.2. The suggestion text (a parameter to mediasearch-did-you-mean) was not being properly sanitized and allowed for the injection and execution of HTML and JavaScript via the intitle: search operator within the query.

An issue was discovered in SpecialEditGrowthConfig in the GrowthExperiments extension in MediaWiki through 1.36.2. The growthexperiments-edit-config-error-invalid-title MediaWiki message was not being properly sanitized and allowed for the injection and execution of HTML and JavaScript.