Public and private virtual hosts - risks?

I’m wondering if there is any risk involved with running several virtual hosts on a machine, all would be private urls (mysite.local, mysite2.local) except for one which would be public (mysite.com). I know I’d have to ensure that if anyone pointed to the external ip of this server, that the public site (mysite.com) was served. My main concern is with the private sites.

I would think that something like this in the vhost config should do the trick.

Require ip 127.0.0.1