ext/libxml/libxml.c in PHP before 5.5.22 and 5.6.x before 5.6.6, when PHP-FPM is used, does not isolate each thread from libxml_disable_entity_loader changes in other threads, which allows remote attackers to conduct XML External Entity (XXE) and XML Entity Expansion (XEE) attacks via a crafted XML document, a related issue to CVE-2015-5161.<a href=http://cwe.mitre.org/data/definitions/611.html>CWE-611: Improper Restriction of XML External Entity Reference ('XXE')</a>
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-8866
