Bypass-SECURITY ISSUE!!!

Hello together,
if this plugin is used on a subdomain and if the main domain redirects to the subdomain the following occurs:

For example with the following domain: sub.domain.com
if domain.com redirects to sub.domain.com there is the following bypass:

Entering the url domain.com and add /wp-admin/options.php then it redirects to sub.domain.com/changedloginurl and you see the login-url and could log in.

I estimate this to be grave, so will there be a fix?

Best regards!!