CVE-2026-54701Markdown Preview Enhanced: Stored XSS via Unsanitized `.crossnote/head.html` Injection in Webview
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.
No exploitation reported and no EPSS estimate yet.
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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 (v4.0, CNA)CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-79
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- 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 0.8.30 | CNA record |
References
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-mcwg-4j78-qwv3x-refsource-confirm
- https://github.com/shd101wyy/crossnote/pull/444x-refsource-misc
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2323x-refsource-misc
- https://github.com/shd101wyy/crossnote/commit/8c55a2ba3365712a1caa4abeece0383bc2994d48x-refsource-misc
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/8bc848b6cbb42b9f35a0f95f7c3bf29b8302970ex-refsource-misc
- https://github.com/shd101wyy/crossnote/releases/tag/0.9.31x-refsource-misc
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.30x-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.