Automatic cPanel updates does not update Perl, instead you have to download them from http://layer1.cpanel.net
Login to your server as root and run the install such as:

# wget http://layer1.cpanel.net/perl587installer.tar.gz
# tar -xzf perl587installer.tar.gz
# cd perl587installer
# ./install

How to test to see if you need to upgrade or not:

# perl -V

Compare the output to current version in http://layer1.cpanel.net

Good luck!