Yum is just a package manager, much like up2date and apt-get. It does not create the packages automatically with updates. It just grabs the rpms requested from whatever place you tell it to in the config. Redhat 9 is EOL which means End Of Life. Redhat no longer release updates for the product. Fedoralegacy.org has taken up the challenge to release updates for redhat 9 however they have not really kept to a routine. They have not had enough volunteers to help keep the project kicking. With a stock redhat 9, even if you have applied all the patches released by fedoralegacy, you will still be out of date. There is another solution, though i can not vouch for them, progeny ( search google ). This might be your best solution if you are unable to migrate the system to a new OS. There are howto's available for migrating redhat 9 to CentOS, I believe i posted one to this forum. Use it at your own risk, especially on a live system. I've done quite a few machines without a problem. CentOS is RedHat's Enterprise linux OS rebuilt from the source they release for their now paid OS. There is no upgrade path to RH enterprise, so if you need the support from Redhat, you will need to get a new machine with RHEL and then migrate all the clients to that new system. Otherwise your probably best going with CentOS.
Have you configured yum to work with fedoralegacy ? This is something you must do on your own, there is no hand holding for such administration tasks by the cpanel software itself.