CVE-2025-53478

The CheckUser extension’s Special:Investigate interface is vulnerable to reflected XSS due to improper escaping of certain internationalized system messages rendered on the “IPs and User agents” tab.

This issue affects Mediawiki – CheckUser 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.

Assigner : security@wikimedia.org

More information : https://gerrit.wikimedia.org/r/q/I3a1e21b6800ff4d813a33ee9fe9b7ccf070b6b2e