Integer overflow in the 16 bit variable reference counter in PHP 4 allows context-dependent attackers to execute arbitrary code by overflowing this counter, which causes the same variable to be destroyed twice, a related issue to CVE-2007-1286.
http://www.securityfocus.com/bid/22765
http://www.novell.com/linux/security/advisories/2007_32_php.html
http://security.gentoo.org/glsa/glsa-200703-21.xml