Greg Roelofs : Security Vulnerabilities, CVEs, Published In 2006 (Overflow)

Buffer overflow in the png_decompress_chunk function in pngrutil.c in libpng before 1.2.12 allows context-dependent attackers to cause a denial of service and possibly execute arbitrary code via unspecified vectors related to "chunk error processing," possibly involving the "chunk_name".

Heap-based buffer overflow in the alpha strip capability in libpng 1.2.7 allows context-dependent attackers to cause a denial of service (crash) when the png_do_strip_filler function is used to strip alpha channels out of the image.