dbcve.org
EmacsApplication · Gnu

CVE-2024-53920

HIGH · 7.8 CVSS v3.1 Published 2024-11-27
Fix available
A fix is available. Upgrade to 30.1 or later.
See remediation →
81/100
Remediation priority · High
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.)

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A code execution vulnerability exists in elisp-mode.el in GNU Emacs before version 30.1. When a user invokes elisp-completion-at-point on untrusted Emacs Lisp source code, or enables on-the-fly diagnosis that triggers byte compilation, unsafe Lisp macro expansion occurs. This allows attackers who can supply malicious elisp source code to execute arbitrary code on the victim's system.

MitigationUpgrade to GNU Emacs 30.1 or later. Until upgraded, avoid opening untrusted Emacs Lisp files and disable on-the-fly byte-compilation/diagnostic features in elisp-mode.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
EmacsApplication
Affected:< 30.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Emacs version
    Run 'emacs --version' or evaluate '(emacs-version)' in Emacs to get the version number
    Affected if Version is earlier than 30.1 (e.g., 29.x, 28.x, etc.)
  2. Verify elisp-mode is in use
    Open any .el file and check the mode line or run 'major-mode' - it should show 'emacs-lisp-mode'
    Affected if Editing Emacs Lisp files in elisp-mode with an Emacs version below 30.1
  3. Confirm on-the-fly diagnostic features
    Check your init.el or directory-local variables for flymake, flycheck, or elisp-diagnostics packages enabled in elisp-mode hooks
    Affected if Flymake, flycheck, or similar diagnostic tools are configured to run automatically in elisp-mode, triggering byte compilation on untrusted code

You are affected if running Emacs version below 30.1 and editing untrusted Emacs Lisp files with elisp-completion-at-point or with diagnostic/byte-compilation features enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 30.1 or later
Fixed in 30.1
Interim mitigation

Upgrade to GNU Emacs 30.1 or later. Until upgraded, avoid opening untrusted Emacs Lisp files and disable on-the-fly byte-compilation/diagnostic features in elisp-mode.

Recommended fix High confidence

Emacs 30.1

  1. Check current Emacs version by running 'emacs --version' to confirm the installed version is below 30.1
  2. Back up your Emacs configuration (typically ~/.emacs, ~/.emacs.d/, or equivalent)
  3. Install GNU Emacs 30.1 or later. For Linux: use your distribution's package manager (e.g., 'sudo apt-get install emacs' after updating repos, or compile from source). For macOS: use Homebrew ('brew install emacs') or MacPorts. For Windows: download from https://www.gnu.org/software/emacs/ or use a package manager like Chocolatey.
  4. Verify the upgrade was successful by running 'emacs --version' and confirming it shows 30.1 or later
  5. Test that elisp-completion-at-point works correctly in the new version
Caveat Review the Emacs 30.1 release notes for any configuration or behavior changes that may affect your setup

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Emacs Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-53920 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-53920 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data