Use After Free
Use-after-free vulnerability in the _zend_shared_memdup function in zend_shared_alloc.c in the OPcache extension in PHP through 5.6.7 allows remote attackers to cause a denial of service or possibly have unspecified other impact via unknown vectors.
CWE-416 - Use After Free
Use-after-free (UaF) vulnerability occurs when the application is using a pointer to memory that has been freed. Any attempt to read/write to a buffer after it is de-allocated allows memory corruption, sensitive information exposure, and can potentially lead to arbitrary code execution.