CVE-2025-53478: Improper Neutralization of Input During Web Page Generation

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 befor...