CVE-2011-1766: Mediawiki

Medium severity, CVSS 5.8. EPSS: 2.2% chance of exploitation in the next 30 days.

includes/User.php in MediaWiki before 1.16.5, when wgBlockDisablesLogin is enabled, does not clear certain cached data after verification of an auth token fails, which allows remote attackers to bypass authentication by creating crafted wikiUserID and wikiUserName cookies, or by leveraging an unattended workstation.

Affected products

• Mediawiki Mediawiki: up to and including 1.16.4; version 1.1.0 only; version 1.2.0 only; version 1.2.1 only; version 1.2.2 only; version 1.2.3 only; …

Published 2011-05-23. Last modified 2026-06-16.