Heap-based buffer overflow in the read_channel_data function in file-psp.c in the Paint Shop Pro (PSP) plugin in GIMP 2.6.11 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a PSP_COMP_RLE (aka RLE compression) image file that begins a long run count at the end of the image.  NOTE: some of these details are obtained from third party information.  NOTE: this vulnerability exists because of an incomplete fix for CVE-2010-4543.