CVE-2023-37303: Mediawiki

Critical severity, CVSS 9.8. EPSS: 1% chance of exploitation in the next 30 days.

An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. In certain situations, an attempt to block a user fails after a temporary browser hang and a DBQueryDisconnectedError error message.

Affected products

• Mediawiki Mediawiki: up to and including 1.39.3

Published 2023-06-30. Last modified 2026-06-17.