A security update for perl in the base system has been committed. To install it, update src/gnu/usr.bin/perl via cvs and rebuild perl. A binary upgrade for newer MirOS #10-beta versions (Linuxtag 2007 and newer) is also available. To install the latter, use
cd / ; sudo tar xvfz /path/to/perl-CVE-2007-5116.cpio.gz
The following ports also had security updates: print/cups (fixed in 1.2.11-1), devel/pcre (fixed in 7.4-0). Please upgrade those if you have them installed.
Update 20071221: cups-1.2.11-3 is out with more fixes.