MediaWiki before 1.23.12, 1.24.x before 1.24.5, 1.25.x before 1.25.4, and 1.26.x before 1.26.1 do not properly sanitize parameters when calling the cURL library, which allows remote attackers to read arbitrary files via an @ (at sign) character in unspecified POST array parameters.
The User::randomPassword function in MediaWiki before 1.23.12, 1.24.x before 1.24.5, 1.25.x before 1.25.4, and 1.26.x before 1.26.1 generates passwords smaller than $wgMinimalPasswordLength, which makes it easier for remote attackers to obtain access via a brute-force attack.
MediaWiki before 1.23.12, 1.24.x before 1.24.5, 1.25.x before 1.25.4, and 1.26.x before 1.26.1 do not properly normalize IP addresses containing zero-padded octets, which might allow remote attackers to bypass intended access restrictions by using an IP address that was not supposed to have been allowed.
The (1) Special:MyPage, (2) Special:MyTalk, (3) Special:MyContributions, (4) Special:MyUploads, and (5) Special:AllMyUploads pages in MediaWiki before 1.23.12, 1.24.x before 1.24.5, 1.25.x before 1.25.4, and 1.26.x before 1.26.1 allow remote attackers to obtain sensitive user login information via crafted links combined with page view statistics.
MediaWiki before 1.23.11, 1.24.x before 1.24.4, and 1.25.x before 1.25.3 uses the thumbnail ImageMagick command line argument, which allows remote attackers to obtain the installation path by reading the metadata of a PNG thumbnail file.
MediaWiki before 1.23.11, 1.24.x before 1.24.4, and 1.25.x before 1.25.3 does not properly restrict access to revisions, which allows remote authenticated users with the viewsuppressed user right to remove revision suppressions via a crafted revisiondelete action, which returns a valid a change form.
MediaWiki before 1.23.11, 1.24.x before 1.24.4, and 1.25.x before 1.25.3 does not throttle file uploads, which allows remote authenticated users to have unspecified impact via multiple file uploads.
The chunked upload API (ApiUpload) in MediaWiki before 1.23.11, 1.24.x before 1.24.4, and 1.25.x before 1.25.3 allows remote authenticated users to cause a denial of service (disk consumption) via a file upload using one byte chunks.
The chunked upload API (ApiUpload) in MediaWiki before 1.23.11, 1.24.x before 1.24.4, and 1.25.x before 1.25.3 does not restrict the uploaded data to the claimed file size, which allows remote authenticated users to cause a denial of service via a chunk that exceeds the file size.
Cross-site scripting (XSS) vulnerability in contrib/cssgen.php in the GeSHi, as used in the SyntaxHighlight_GeSHi extension and MediaWiki before 1.23.10, 1.24.x before 1.24.3, and 1.25.x before 1.25.2, allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.