Cross-site scripting (XSS) vulnerability in includes/actions/InfoAction.php in MediaWiki before 1.21.9 and 1.22.x before 1.22.6 allows remote attackers to inject arbitrary web script or HTML via the sort key in an info action.

includes/upload/UploadBase.php in MediaWiki before 1.19.12, 1.20.x and 1.21.x before 1.21.6, and 1.22.x before 1.22.3 does not prevent use of invalid namespaces in SVG files, which allows remote attackers to conduct cross-site scripting (XSS) attacks via an SVG upload, as demonstrated by use of a W3C XHTML namespace in conjunction with an IFRAME element.

includes/User.php in MediaWiki before 1.19.12, 1.20.x and 1.21.x before 1.21.6, and 1.22.x before 1.22.3 terminates validation of a user token upon encountering the first incorrect character, which makes it easier for remote attackers to obtain access via a brute-force attack that relies on timing differences in responses to incorrect token guesses.

Cross-site scripting (XSS) vulnerability in the formatHTML function in includes/api/ApiFormatBase.php in MediaWiki before 1.19.12, 1.20.x and 1.21.x before 1.21.6, and 1.22.x before 1.22.3 allows remote attackers to inject arbitrary web script or HTML via a crafted string located after http:// in the text parameter to api.php.

MediaWiki before 1.19.6 and 1.20.x before 1.20.5 allows remote attackers to conduct cross-site scripting (XSS) attacks, as demonstrated by a CDATA section containing valid UTF-7 encoded sequences in a SVG file, which is then incorrectly interpreted as UTF-8 by Chrome and Firefox.

MediaWiki before 1.19.6 and 1.20.x before 1.20.5 does not allow extensions to prevent password changes without using both Special:PasswordReset and Special:ChangePassword, which allows remote attackers to bypass the intended restrictions of an extension that only implements one of these blocks.

The resource loader in MediaWiki 1.17.x before 1.17.3 and 1.18.x before 1.18.2 includes private data such as CSRF tokens in a JavaScript file, which allows remote attackers to obtain sensitive information.

Cross-site request forgery (CSRF) vulnerability in Special:Upload in MediaWiki 1.17.x before 1.17.3 and 1.18.x before 1.18.2 allows remote attackers to hijack the authentication of unspecified victims for requests that upload files.

The wikitext parser in MediaWiki 1.17.x before 1.17.3 and 1.18.x before 1.18.2 allows remote attackers to cause a denial of service (infinite loop) via certain input, as demonstrated by the padleft function.

Multiple cross-site request forgery (CSRF) vulnerabilities in MediaWiki 1.17.x before 1.17.3 and 1.18.x before 1.18.2 allow remote attackers to hijack the authentication of users with the block permission for requests that (1) block a user via a request to the Block module or (2) unblock a user via a request to the Unblock module.