CVE-2026-54566
CVE-2026-54566 · Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Markdown Preview Enhanced is a Markdown preview extension for Visual Studio Code. Prior to 0.8.29, Markdown Preview Enhanced evaluates repository-controlled .crossnote/config.js and .crossnote/parser.js files with vm.runInNewContext, which does not provide a security boundary from the Node.js host realm. Opening a Markdown file in a malicious repository automatically loads these files, and prototype-chain traversal can reach the host Function constructor and process object, allowing operating-system commands to execute as the victim account without further interaction. Both configuration evaluation and parser-hook evaluation are affected, and the attack does not depend on module-scoped require being available. This issue is fixed in version 0.8.29.
CVSS 8.5 · High · EPSS 0.3%
- Published
- Updated
Affected products and versions
vscode-markdown-preview-enhanced
- Versions
- < 0.8.29: Affected
No fix published
Original sources
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch
- https://github.com/shd101wyy/crossnote/pull/443
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2320
- https://github.com/shd101wyy/crossnote/commit/e4890d64502e53b717cce0cb73f1a78b244dc640
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4c
- https://github.com/shd101wyy/crossnote/releases/tag/0.9.30
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.29
- https://nvd.nist.gov/vuln/detail/CVE-2026-54566