CVE-2026-54702

Markdown Preview Enhanced is a Markdown preview extension for Visual Studio Code. Prior to 0.8.30, the webview message handler in src/preview-provider.ts accepts an attacker-controlled command value and attacker-controlled args, constructs a command in the _crossnote namespace, and invokes vscode.commands.executeCommand without an allowlist or type validation. JavaScript already executing in the preview webview can use this bridge to invoke privileged extension commands, including file modification, code-chunk execution, export-tool execution, and arbitrary URL opening, with attacker-selected arguments. Exploitation requires a separate webview JavaScript execution path, such as the independently tracked .crossnote/head.html injection, but no further authorization check protects the extension-host command boundary. This issue is fixed in version 0.8.30.

CVSS

No CVSS.

References

Link	Resource
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/8bc848b6cbb42b9f35a0f95f7c3bf29b8302970e
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2323
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.30
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-83c6-hcjv-pvmg
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-83c6-hcjv-pvmg

Configurations

No configuration.

History

15 Oct 2026, 17:17

Type	Values Removed	Values Added
References	~~() https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-83c6-hcjv-pvmg -~~	() https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-83c6-hcjv-pvmg -

14 Oct 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-14 20:17

Updated : 2026-10-16 16:00

NVD link : CVE-2026-54702

Mitre link : CVE-2026-54702

CVE.ORG link : CVE-2026-54702

JSON object : View

Products Affected

No product.

CWE

CWE-749

Exposed Dangerous Method or Function

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