On an official server (NL 3663870), while at Tisy Military Base I was attacked by wolves which had managed to clip through the walls/floor of the hangar style building located in the center of the military base (just north of the industrial & shipping containers).
The hangar is one which you are able to stand on top of (like a grassy knoll), the wolves were running all over the top, and around the front of the hangar.

All the doors were shut (front hangar doors, the back door, and the door to final back room where I was cowering for my life), and still the wolves were able to get into the hangar and then through the wall into the back room.