The following errata for CentOS-2 have been built and uploaded the the centos mirror:

RHSA-2004:344-01 Updated semi packages fix flim vulnerability

Files available: semi-1.14.3-8.72.EL.1.noarch.rpm: semi-xemacs-1.14.3-8.72.EL.1.noarch.rpm:

More details are available from the RedHat web site at https://rhn.redhat.com/errata/rh21as-errata.html

The easy way to make sure you are up to date with all the latest patches is to run: # yum update