Use-after-free vulnerability in the process_nested_data function in ext/standard/var_unserializer.re in PHP before 5.4.36, 5.5.x before 5.5.20, and 5.6.x before 5.6.4 allows remote attackers to execute arbitrary code via a crafted unserialize call that leverages improper handling of duplicate keys within the serialized properties of an object, a different vulnerability than CVE-2004-1019.<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-2014-8142