For users still on older versions, upgrading is strongly recommended via the official mIRC download page to protect against the URI protocol vulnerability. Latest News - mIRC
Version 7.55 introduced stricter handling of URI protocol handlers to block these exploit paths. Key Features and Enhancements mIRC 7.55 - SeuPirate
In versions prior to 7.55, attackers could use malicious irc:// links to pass command-line arguments to mIRC. For users still on older versions, upgrading is
mIRC version 7.55 is a major release of the popular Internet Relay Chat (IRC) client, primarily noted for addressing critical security vulnerabilities and improving modern Windows compatibility. For users still on older versions