MediaWiki CheckUser Extension Reflected Cross-Site Scripting Vulnerability

A reflected cross-site scripting vulnerability has been identified in the CheckUser extension of MediaWiki. This issue arises in the Special:Investigate interface, specifically on the 'IPs and User agents' tab, due to improper escaping of certain internationalized system messages. The vulnerability affects CheckUser extension versions for MediaWiki from 1.39.X prior to 1.39.13, from 1.42.X prior to 1.42.7, and from 1.43.X prior to 1.43.2.

Impact

Exploitation of this vulnerability allows for reflected cross-site scripting, where an attacker can inject malicious scripts that are executed in the context of the user's browser.