CentOS Errata and Security Advisory 2005:498
https://rhn.redhat.com/errata/RHSA-2005-498.html
The following updated files have been uploaded and are currently syncing to the mirrors:
x86_64: spamassassin-3.0.4-1.el4.x86_64.rpm
src: spamassassin-3.0.4-1.el4.src.rpm