Red Hat typically backports the updates, security fixes and other enhancements to the kernels they release, do not let the version number be your only guide. It is a bit like comparing red apples to green apples, see;
http://www.redhat.com/security/updat...g/?sc_cid=3093
With that said one can use the updated kernels from Fedora Core 6;
http://download.fedora.redhat.com/pu...ore/updates/6/
Get the list of your installed kernel packages; rpm -qa --qf="%{n}-%{v}-%{r}.%{arch}n" 'kernel*'
Download the matching updated kernel rpm packages and install them; rpm -ivh kernel*.rpm