CVE-2026-54701

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 4.0

6.9CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 22% of CVEs (scores of 2026-10-25)

CWE

CWE-79

Published

2026-10-14

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

References

• https://github.com/shd101wyy/crossnote/commit/8c55a2ba3365712a1caa4abeece0383bc2994d48
• https://github.com/shd101wyy/crossnote/pull/444
• https://github.com/shd101wyy/crossnote/releases/tag/0.9.31
• https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/8bc848b6cbb42b9f35a0f95f7c3bf29b8302970e
• https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2323

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