CentOS Errata and Security Advisory 2006:0205
https://rhn.redhat.com/errata/RHSA-2006-0205.html
The following updated files have been uploaded and are currently syncing to the mirrors:
s390: updates/s390/RPMS/libpng-1.2.7-1.el4.2.s390.rpm updates/s390/RPMS/libpng-devel-1.2.7-1.el4.2.s390.rpm
s390x: updates/s390x/RPMS/libpng-1.2.7-1.el4.2.s390x.rpm updates/s390x/RPMS/libpng-devel-1.2.7-1.el4.2.s390x.rpm