CVE-2026-11422 Markdown Preview Enhanced 0.8.x Code Injection via WaveDrom Rendering
Attackers can execute arbitrary JavaScript and write files by embedding malicious content in WaveDrom blocks within Markdown documents processed by the extension.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-11422?
CVE-2026-11422 is a high-severity code injection vulnerability in shd101wyy Markdown Preview Enhanced, published on 5 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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.
Weakness: CWE-95
Which versions are affected by CVE-2026-11422?
How do I fix CVE-2026-11422?
No fix has been published for CVE-2026-11422 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-11422 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-11422 exists.
Sources
Also known as GHSA-m48c-hxqg-4j76.