you should always keep your system and services/scripts up-to-date by upgrading them to the latest version available.
it also depends on what gnu/linux distribution your server is running on. that being said, you're almost always safe to upgrade if you're running a 'stable release' distribution.
on the other hand, if you're running more cutting/bleeding edge distribution, then you should do a research before upgrading.
anyway, in both cases, one is encouraged to check and verify the services are running as expected after the upgrade.
Originally Posted by kendel
...is it worth it or better not to update.
of course it is, especially if the upgrade fixes some critical vulnerabilities