The png_do_expand_palette function in libpng before 1.6.8 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via (1) a PLTE chunk of zero bytes or (2) a NULL palette, related to pngrtran.c and pngset.c.
Integer signedness error in the png_inflate function in pngrutil.c in libpng before 1.4.10beta01, as used in Google Chrome before 17.0.963.83 and other products, allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted PNG file, a different vulnerability than CVE-2011-3026.