Buffer overflow in the png_set_PLTE function in libpng before 1.0.65, 1.1.x and 1.2.x before 1.2.55, 1.3.x, 1.4.x before 1.4.18, 1.5.x before 1.5.25, and 1.6.x before 1.6.20 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a small bit-depth value in an IHDR (aka image header) chunk in a PNG image. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-8126.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.