Ubuntu Security Notice 1126-2 - USN 1126-1 fixed several vulnerabilities in PHP. The fix for CVE-2010-4697 introduced an incorrect reference counting regression in the Zend engine that caused the PHP interpreter to segfault. This regression affects Ubuntu 6.06 LTS and Ubuntu 8.04 LTS.
d3109ede1f1b610fb18480ae30cb346b0d85aac84aedfeadd43a5eb1ad6fe0a2