Use-after-free vulnerability in the spl_ptr_heap_insert function in ext/spl/spl_heap.c in PHP before 5.5.27 and 5.6.x before 5.6.11 allows remote attackers to execute arbitrary code by triggering a failed SplMinHeap::compare operation.<a href=http://cwe.mitre.org/data/definitions/416.html>CWE 416: Use After Free</a> http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-4116