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

RHSA-2008:0546-01 Moderate: php security update

Files available: php-4.1.2-2.20.i386.rpm php-devel-4.1.2-2.20.i386.rpm php-imap-4.1.2-2.20.i386.rpm php-ldap-4.1.2-2.20.i386.rpm php-manual-4.1.2-2.20.i386.rpm php-mysql-4.1.2-2.20.i386.rpm php-odbc-4.1.2-2.20.i386.rpm php-pgsql-4.1.2-2.20.i386.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