CentOS Errata and Security Advisory 2007:0153
https://rhn.redhat.com/errata/RHSA-2007-0153.html
The following updated files have been uploaded and are currently syncing to the mirrors:
x86_64: php-5.1.6-11.el5.x86_64.rpm php-bcmath-5.1.6-11.el5.x86_64.rpm php-cli-5.1.6-11.el5.x86_64.rpm php-common-5.1.6-11.el5.x86_64.rpm php-dba-5.1.6-11.el5.x86_64.rpm php-devel-5.1.6-11.el5.x86_64.rpm php-gd-5.1.6-11.el5.x86_64.rpm php-imap-5.1.6-11.el5.x86_64.rpm php-ldap-5.1.6-11.el5.x86_64.rpm php-mbstring-5.1.6-11.el5.x86_64.rpm php-mysql-5.1.6-11.el5.x86_64.rpm php-ncurses-5.1.6-11.el5.x86_64.rpm php-odbc-5.1.6-11.el5.x86_64.rpm php-pdo-5.1.6-11.el5.x86_64.rpm php-pgsql-5.1.6-11.el5.x86_64.rpm php-snmp-5.1.6-11.el5.x86_64.rpm php-soap-5.1.6-11.el5.x86_64.rpm php-xml-5.1.6-11.el5.x86_64.rpm php-xmlrpc-5.1.6-11.el5.x86_64.rpm
src: php-5.1.6-11.el5.src.rpm