CVE-2023-45367: Mediawiki

Medium severity, CVSS 6.5. EPSS: 0.7% chance of exploitation in the next 30 days.

An issue was discovered in the CheckUser extension for MediaWiki before 1.35.12, 1.36.x through 1.39.x before 1.39.5, and 1.40.x before 1.40.1. A user can use a rest.php/checkuser/v0/useragent-clienthints/revision/ URL to store an arbitrary number of rows in cu_useragent_clienthints, leading to a denial of service.

Affected products

• Mediawiki Mediawiki: before 1.35.12 (fixed in 1.35.12); from 1.36.0, before 1.39.5 (fixed in 1.39.5); version 1.40.0 only

Published 2023-10-09. Last modified 2026-06-17.