CentOS Errata and Security Advisory 2007:0203
https://rhn.redhat.com/errata/RHSA-2007-0203.html
The following updated files have been uploaded and are currently syncing to the mirrors:
s390: updates/s390/RPMS/unzip-5.51-9.EL4.5.s390.rpm
s390x: updates/s390x/RPMS/unzip-5.51-9.EL4.5.s390x.rpm