Multiple cross-site scripting (XSS) vulnerabilities in MediaWiki before 1.18.5 and 1.19.x before 1.19.2, when unspecified JavaScript gadgets are used, allow remote attackers to inject arbitrary web script or HTML via the userlang parameter to w/index.php.

MediaWiki before 1.18.5, and 1.19.x before 1.19.2 does not send a restrictive X-Frame-Options HTTP header, which allows remote attackers to conduct clickjacking attacks via an embedded API response in an IFRAME element.

MediaWiki before 1.18.5, and 1.19.x before 1.19.2 allows remote attackers to bypass GlobalBlocking extension IP address blocking and create an account via unspecified vectors.

MediaWiki before 1.18.5, and 1.19.x before 1.19.2 does not properly protect user block metadata, which allows remote administrators to read a user block reason via a reblock attempt.

The getid3 library in MediaWiki before 1.24.1, 1.23.8, 1.22.15 and 1.19.23 allows remote attackers to read arbitrary files, cause a denial of service, or possibly have other impact via an XML External Entity (XXE) attack. NOTE: Related to CVE-2014-2053.

The MWOAuthDataStore::lookup_token function in Extension:OAuth for MediaWiki 1.25.x before 1.25.3, 1.24.x before 1.24.4, and before 1.23.11 does not properly validate the signature when checking the authorization signature, which allows remote registered Consumers to use another Consumer's credentials by leveraging knowledge of the credentials.

Cross-site scripting (XSS) vulnerability in the Parser::replaceInternalLinks2 method in MediaWiki before 1.23.15, 1.26.x before 1.26.4, and 1.27.x before 1.27.1 allows remote attackers to inject arbitrary web script or HTML via vectors involving replacement of percent encoding in unclosed internal links.

MediaWiki before 1.23.15, 1.26.x before 1.26.4, and 1.27.x before 1.27.1 does not generate head items in the context of a given title, which allows remote attackers to obtain sensitive information via a parse action to api.php.

ApiParse in MediaWiki before 1.23.15, 1.26.x before 1.26.4, and 1.27.x before 1.27.1 allows remote attackers to bypass intended per-title read restrictions via a parse action to api.php.

Cross-site scripting (XSS) vulnerability in the CSS user subpage preview feature in MediaWiki before 1.23.15, 1.26.x before 1.26.4, and 1.27.x before 1.27.1 allows remote attackers to inject arbitrary web script or HTML via the edit box in Special:MyPage/common.css.