php: mb_strcut() Negative size parameter in memcpy

Multiple integer overflows in the mbflstrcut function in ext/mbstring/libmbfl/mbfl/mbfilter.c in PHP before 5.5.34, 5.6.x before 5.6.20, and 7.x before 7.0.5 allow remote attackers to cause a denial of service application crash or possibly execute arbitrary code via a crafted mbstrcut call...