$ perl -MCGI -sE 'say $CGI::VERSION'
4.13
$ perl -MCGI -E 'no warnings; my $x=CGI->new; $,=", ";
  say $x->param("x"); say "didnt die"' -- x=foo x=bar
CGI::param called in list context from package main line 1, this can lead to vulnerabilities. See the warning in "Fetching the value or values of a single named parameter" at /opt/perl5.20/lib/site_perl/5.20.0/CGI.pm line 437.
foo, bar
didnt die
$ perl -MCGI -E 'use warnings; my $x=CGI->new; $,=", ";
  say $x->param("x"); say "didnt die"' -- x=foo x=bar
CGI::param called in list context from package main line 1, ...
foo, bar
didnt die
$ perl -MCGI -E 'use warnings FATAL=>"all"; my $x=CGI->new;
  $,=", "; say $x->param("x"); say "didnt die"' -- x=foo x=bar
CGI::param called in list context from package main line 1, ...
foo, bar
didnt die