CVE-2026-54701
CVE-2026-54701 · Markdown Preview Enhanced: Stored XSS via Unsanitized `.crossnote/head.html` Injection in Webview
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 0.8.30, Markdown Preview Enhanced reads repository-controlled .crossnote/head.html content and passes it through resolvePathsInHeader before inserting it into the head of the preview webview document without removing executable content. Script-capable markup executes while the document loads, before the React application and DOMPurify initialize, and can access acquireVsCodeApi to send messages from the webview to the extension host. Opening a Markdown preview in a malicious repository is sufficient to trigger the injected content, and no additional click within the notification or preview is required. This issue is fixed in version 0.8.30.
CVSS 6.9 · Medium · EPSS 0.2%
- Published
- Updated
Affected products and versions
vscode-markdown-preview-enhanced
- Versions
- < 0.8.30: Affected
No fix published
Original sources
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-mcwg-4j78-qwv3
- https://github.com/shd101wyy/crossnote/pull/444
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2323
- https://github.com/shd101wyy/crossnote/commit/8c55a2ba3365712a1caa4abeece0383bc2994d48
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/8bc848b6cbb42b9f35a0f95f7c3bf29b8302970e
- https://github.com/shd101wyy/crossnote/releases/tag/0.9.31
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.30
- https://nvd.nist.gov/vuln/detail/CVE-2026-54701