CVE-2025-53487: Wikimedia Foundation Mediawiki - Approvedrevs Extension

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

The ApprovedRevs extension for MediaWiki is vulnerable to stored XSS in multiple locations where system messages are inserted into raw HTML without proper escaping. Attackers can exploit this by injecting JavaScript payloads via the uselang=x-xss language override, which causes crafted message keys to be rendered unescaped. This issue affects Mediawiki - ApprovedRevs extension: from 1.39.X before 1.39.13, from 1.42.X before 1.42.7, from 1.43.X before 1.43.2.

Affected products

• Wikimedia Foundation Mediawiki - Approvedrevs Extension: from 1.39, before 1.39.13 (fixed in 1.39.13); from 1.42, before 1.42.7 (fixed in 1.42.7); from 1.43, before 1.43.2 (fixed in 1.43.2)

Published 2025-07-07. Last modified 2026-06-17.