CentOS Errata and Security Advisory 2007:1130
https://rhn.redhat.com/errata/RHSA-2007-1130.html
The following updated files have been uploaded and are currently syncing to the mirrors:
s390: updates/s390/RPMS/squid-2.5.STABLE3-8.3E.s390.rpm
s390x: updates/s390x/RPMS/squid-2.5.STABLE3-8.3E.s390x.rpm