Removing the `print' command, and running on Solaris, definitely shows a memory leak (at around 0.4MB/sec) if I run with Perl 5.005.

% uname -a
SunOS mir 5.8 Generic_108528-07 sun4u sparc SUNW,Ultra-2
% perl -MCGI -le 'print $CGI::VERSION'
2.46
[download]

Running with Perl 5.6.1 on the same platform, I observe no memory leak. This is strange.