Out-of-bounds

The WriteOnePNGImage function in coders/png.c in GraphicsMagick 1.3.26 allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted file, because the program’s actual control flow was inconsistent with its indentation. This resulted in a logging statement executing outside of a loop, and consequently using an invalid array index corresponding to the loop’s exit condition.