Use-after-free vulnerability in the wddx_stack_destroy function in ext/wddx/wddx.c in PHP before 5.6.26 and 7.x before 7.0.11 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a wddxPacket XML document that lacks an end-tag for a recordset field element, leading to mishandling in a wddx_deserialize call.