CentOS Errata and Security Advisory 2007:0074
https://rhn.redhat.com/errata/RHSA-2007-0074.html
The following updated files have been uploaded and are currently syncing to the mirrors:
s390: updates/s390/RPMS/spamassassin-3.1.8-2.el4.s390.rpm
s390x: updates/s390x/RPMS/spamassassin-3.1.8-2.el4.s390x.rpm