CVE-2023-37300: Mediawiki

Medium severity, CVSS 5.3. EPSS: 0.7% chance of exploitation in the next 30 days.

An issue was discovered in the CheckUserLog API in the CheckUser extension for MediaWiki through 1.39.3. There is incorrect access control for visibility of hidden users.

Affected products

• Mediawiki Mediawiki: up to and including 1.39.3

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