In elisp-mode.el in GNU Emacs before 30.1, a user who chooses to invoke elisp-completion-at-point (for code completion) on untrusted Emacs Lisp source code can trigger unsafe Lisp macro expansion that allows attackers to execute arbitrary code. (This unsafe expansion also occurs if a user chooses to enable on-the-fly diagnosis that byte compiles untrusted Emacs Lisp source code.)
In Emacs before 29.4, org-link-expand-abbrev in lisp/ol.el expands a %(...) link abbrev even when it specifies an unsafe function, such as shell-command-to-string. This affects Org Mode before 9.7.5.
Stack-based buffer overflow in emacs allows user-assisted attackers to cause a denial of service (application crash) and possibly have unspecified other impact via a large precision value in an integer format string specifier to the format function, as demonstrated via a certain "emacs -batch -eval" command line.