Threats affecting pkg:github/emacs-mirror/emacs

A code execution flaw was found in Emacs, affecting versions prior to 31.2. The Flymake mode using language backends other than Lisp would execute arbitrary code from the edited file while performing syntax checking. Viewing or editing untrusted files using Emacs could lead to arbitrary code execution with the privileges of the user running Emacs.

GNU Emacs before 31.0.91 contains an integer overflow in the PBM/PPM/PGM image loader that allows an attacker to leak heap memory contents by supplying a crafted image with large dimensions and an elevated max color index. The image loader multiplies image dimensions and channel count using signed integer arithmetic; for sufficiently large values, the result wraps to a negative number, bypassing the bounds check and causing the pixel reader to access heap memory past the end of the allocated buffer. The over-read contents are interpreted as pixel color values and rendered on screen.