CVE-2015-6818

The decode_ihdr_chunk function in libavcodec/pngdec.c in FFmpeg before 2.7.2 does not enforce uniqueness of the IHDR (aka image header) chunk in a PNG image, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via a crafted image with two or more of these chunks.