CVE-2025-53480 — CheckUser: Reflected Cross-Site Scripting (XSS) in Special:Investigate (Account information tab) via unsanitized i18n messages
The CheckUser extension’s Special:Investigate page has a vulnerability in the Account information tab, where specific internationalized messages are rendered without proper esca…
Published: 2025-07-08 · CVSS: 5.4 · CVSS 3.1
The CheckUser extension’s Special:Investigate page has a vulnerability in the Account information tab, where specific internationalized messages are rendered without proper escaping. Attackers can exploit this by appending ?uselang=x-xss to the URL, causing reflected XSS when the UI renders affected message keys. 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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7