When running under mod_perl, all Perl code shares the same
interpreter. This means that every application can access data from
every other application. Embperl maintains a separate namespace for
every document, which is enough to avoid accidentally overwriting
other applications data, but there is no real security. You can access
any data from any other application that runs on the same server process
under mod_perl if you explicitly specify a package name.
This is not a problem of Embperl itself, but caused by the design of
Apache and mod_perl.