CVE-2024-53920
Medium
Elevated severity or exploit probability.
CVSS base
7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.6%
49.1th percentile
CISA KEV
Not listed
Weakness / dates
CWE-94
Published 2024-11-27 · modified 2026-09-14
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | R | Required |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2024-11-27 — Published (NVD)
- 2026-09-14 — Last modified (NVD)
Description
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.)
Affected
References
- https://eshelyaron.com/posts/2024-11-27-emacs-aritrary-code-execution-and-how-to-avoid-it.html
- https://git.savannah.gnu.org/cgit/emacs.git/tag/?h=emacs-30.0.92
- https://git.savannah.gnu.org/cgit/emacs.git/tree/ChangeLog.4
- https://git.savannah.gnu.org/cgit/emacs.git/tree/etc/NEWS?h=emacs-30.1
- https://news.ycombinator.com/item?id=42256409
- https://yhetil.org/emacs/CAFXAjY5f4YfHAtZur1RAqH34UbYU56_t6t2Er0YEh1Sb7-W=hg@mail.gmail.com/
- http://www.openwall.com/lists/oss-security/2026/08/20/3
- http://www.openwall.com/lists/oss-security/2026/08/20/7
- http://www.openwall.com/lists/oss-security/2026/09/14/1
- https://lists.debian.org/debian-lts-announce/2025/02/msg00033.html