The admin API module in the QuizGame extension for MediaWiki through 1.37.2 (before 665e33a68f6fa1167df99c0aa18ed0157cdf9f66) omits a check for the quizadmin user.
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. Some unprivileged users can view confidential information (e.g., IP addresses and User-Agent headers for election traffic) on a testwiki SecurePoll instance.