Emacs 21 and XEmacs automatically load and execute .flc (fast lock) files that are associated with other files that are edited within Emacs, which allows user-assisted attackers to execute arbitrary code.
Multiple integer overflows in glyphs-eimage.c in XEmacs 21.4.22, when running on Windows, allow remote attackers to cause a denial of service (crash) or execute arbitrary code via (1) the tiffinstantiate function processing a crafted TIFF file, (2) the pnginstantiate function processing a crafted PNG file, and (3) the jpeginstantiate function processing a crafted JPEG file, all which trigger a heap-based buffer overflow. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.