The zend_inline_hash_func function in php-luasandbox in the Scribuntu extension for MediaWiki before 1.19.10, 1.2x before 1.21.4, and 1.22.x before 1.22.1 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via vectors related to converting Lua data structures to PHP, as demonstrated by passing { [{}] = 1 } to a module function.

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/specials/SpecialChangePassword.php in MediaWiki before 1.19.14, 1.20.x and 1.21.x before 1.21.8, and 1.22.x before 1.22.5 does not properly handle a correctly authenticated but unintended login attempt, which makes it easier for remote authenticated users to obtain sensitive information by arranging for a victim to login to the attacker's account, as demonstrated by tracking the victim's activity, related to a "login CSRF" issue.

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.

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.

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.

MediaWiki 1.22.x before 1.22.2, 1.21.x before 1.21.5, and 1.19.x before 1.19.11, when DjVu or PDF file upload support is enabled, allows remote attackers to execute arbitrary commands via shell metacharacters in (1) the page parameter to includes/media/DjVu.php; (2) the w parameter (aka width field) to thumb.php, which is not properly handled by includes/media/PdfHandler_body.php; and possibly unspecified vectors in (3) includes/media/Bitmap.php and (4) includes/media/ImageHandler.php.