GNOME gdk-pixbuf (aka GdkPixbuf) before 2.42.2 allows a denial of service (infinite loop) in lzw.c in the function write_indexes. if c->self_code equals 10 self->code_table10.extends will assign the value 11 to c. The next execution in the loop will assign self->code_table11.extends to c which will give the value of 10. This will make the loop run infinitely. This bug can for example be triggered by calling this function with a GIF image with LZW compression that is crafted in a special way.