All vulnerabilities
CVE-2026-54566GHSA-427h-jhpr-8jch

vscode-markdown-preview-enhanced: Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`

shd101wyy vscode-markdown-preview-enhanced
Open in ThreatlineRecord JSON
CVSS
8.5High
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 14 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.30%Chance of exploitation activity in the next 30 days, higher than 21% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published14 Oct 2026Updated 14 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

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.

Text from CVE List

Affected versions 1

  • vscode-markdown-preview-enhancedaffected: < 0.8.29CVE List

References 7