Integer overflow in the gdImageWebpCtx function in gd_webp.c in the GD Graphics Library (aka libgd) through 2.2.3, as used in PHP through 7.0.11, allows remote attackers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via crafted imagewebp and imagedestroy calls. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-7568