No patched version is available. Reported to the WordPress plugin review team on 2023 Feb 27.
Mika discovered and reported this Cross Site Scripting (XSS) vulnerability in WordPress IFrame Shortcode Plugin. This could allow a malicious actor to inject malicious scripts, such as redirects, advertisements, and other HTML payloads into your website which will be executed when guests visit your site. This vulnerability has not been known to be fixed yet.