Netpbm before 10.86.51, 11.x before 11.02.30, and 11.03 before 11.15.08 contains a stack-based buffer overflow in picttoppm's scanPoly() function in converter/ppm/picttoppm.c. Attackers can supply a crafted PICT file whose polygon edges produce more than 5000 points, overflowing the coord stack array to crash the converter or potentially execute code.