Oh my, this is such a stupid mistake. It went undiscovered only because I always used CGI scripts on the first vhost (and hence the offset would be 0) and never on the others.

the executor forks to spawn the cgi scripts, and they inherit the socket for communication with the listener process. Make that impossible.

"test" was replaced by "regress" a while ago

It's how httpd(8) does it, and it allows us to call fnmatch less time