---
id: CVE-2026-78847
title: >-
  An issue in gray-matter All versions (verified on 4.0.3) allows the JavaScript
  engine in lib/engines.js using eval() to parse front matter when language is
  js/javascript.This allows arbitrary code execution.
summary: >-
  An issue in gray-matter All versions (verified on 4.0.3) allows the JavaScript
  engine in lib/engines.js using eval() to parse front matter when language is
  js/javascript.This allows arbitrary code execution.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-95
published: '2026-09-21'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T20:00:03.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-78847'
references:
  - url: 'https://blog.checo.cc/en/posts/Security/1'
    label: cve@mitre.org
  - url: 'https://github.com/jonschlinkert/gray-matter/issues/112'
    label: cve@mitre.org
  - url: 'https://github.com/jonschlinkert/gray-matter/issues/131'
    label: cve@mitre.org
  - url: 'https://github.com/jonschlinkert/gray-matter/issues/182'
    label: cve@mitre.org
  - url: 'https://github.com/jonschlinkert/gray-matter/issues/182'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00866
epssPercentile: 0.5696
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-22T15:12:23.119470Z'
ingestedAt: '2026-09-21T21:53:57.426Z'
---

## Overview

An issue in gray-matter All versions (verified on 4.0.3) allows the JavaScript engine in lib/engines.js using eval() to parse front matter when language is js/javascript.This allows arbitrary code execution.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.