Vulnerability · Published Jun 5, 2026 · Assigned by VulnCheck
CVE-2026-11422Markdown Preview Enhanced 0.8.x Code Injection via WaveDrom Rendering
High 7.1
In plain English
A high-severity security flaw in crossnote from shd101wyy. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).
Official description
Markdown Preview Enhanced 0.8.x with crossnote engine 0.9.28 contains a code injection vulnerability in the WaveDrom rendering pipeline that allows attackers to execute arbitrary JavaScript by embedding malicious content in a wavedrom fenced code block within a crafted Markdown document. Attackers can exploit the unsanitized passing of wavedrom block content to window.eval() in the VS Code webview context to abuse the extension's message passing and invoke arbitrary file writes on the local filesystem.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| shd101wyy | Markdown Preview Enhanced | 0 – before 0.8.27 |
| shd101wyy | crossnote | 0 – before 0.9.28 |
Weakness: CWE-95 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
References
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/issues/2315 issue-tracking
- https://github.com/shd101wyy/crossnote/commit/5588ca2121c3da43fe331575dc5cf4ef347b91ee patch
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/dcd80281c986293b93d9f1af34ced64dcb230c77 patch
- https://www.vulncheck.com/advisories/markdown-preview-enhanced-x-code-injection-via-wavedrom-rendering third-party-advisory