There is no definitive answer to this question. In some cases Fantastico can upgrade the software it has installed, but it may also report that an upgrade must be performed manually.
To see if there is an upgrade for your software, login to cPanel and click on Fantastico. If there is a new version, this will be reported on the first page.
In either case, Umbrella Host recommends you make a full backup of your database and files before upgrading any software.