CVE-2026-78847

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Published 2026-09-21. Last modified 2026-09-22.