Buffer overflow in the date_from_ISO8601 function in the mkgmtime implementation in libxmlrpc/xmlrpc.c in the XMLRPC extension in PHP before 5.4.34, 5.5.x before 5.5.18, and 5.6.x before 5.6.2 allows remote attackers to cause a denial of service (application crash) via (1) a crafted first argument to the xmlrpc_set_type function or (2) a crafted argument to the xmlrpc_decode function, related to an out-of-bounds read operation.