Red Hat GIMP: out-of-bounds read

A flaw was found in GIMP. The PSD thumbnail resource loader performs a BGR-to-RGB channel swap with a fixed 3-byte stride and does not verify that the JPEG thumbnail is RGB. A crafted grayscale PSD thumbnail can cause a heap out-of-bounds read and write in the plug-in process, leading to a crash and potentially arbitrary code execution when the victim browses or opens the file.