CVE-2026-54566Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`
Updated under an hour ago ()
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It affects shd101wyy vscode-markdown-preview-enhanced. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.30%, higher than 21% of scored CVEs.
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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 (v4.0, CNA)CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-94
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.30% (percentile 21)
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 14, 2026
Affected products
shd101wyy vscode-markdown-preview-enhanced shd101wyy:vscode_markdown_preview_enhanced (from the name) | before 0.8.29 | CNA record |
References
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jchx-refsource-confirm
- https://github.com/shd101wyy/crossnote/pull/443x-refsource-misc
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2320x-refsource-misc
- https://github.com/shd101wyy/crossnote/commit/e4890d64502e53b717cce0cb73f1a78b244dc640x-refsource-misc
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4cx-refsource-misc
- https://github.com/shd101wyy/crossnote/releases/tag/0.9.30x-refsource-misc
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.29x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.