CentOS Errata and Security Advisory 2005:415
https://rhn.redhat.com/errata/RHSA-2005-415.html
The following updated files have been uploaded and are currently syncing to the mirrors:
x86_64: squid-2.5.STABLE6-3.4E.9.i386.rpm
src: squid-2.5.STABLE6-3.4E.9.src.rpm