Quick answers
- Is CVE-2026-50733 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-50733 being exploited in the wild.
- How severe is CVE-2026-50733?
- High severity, with a CVSS score of 8.8, published 5 June 2026.
- Which products and versions are affected?
- Shd101wyy Markdown Preview Enhanced < 0.8.28.
- Is there a fix for CVE-2026-50733?
- A patch was published on 2026-06-05: Version 0.8.28 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-50733 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-50733?
- Check whether you run Shd101wyy Markdown Preview Enhanced at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An eval injection vulnerability exists in Markdown Preview Enhanced due to the unsafe use of window.eval() when parsing WaveDrom diagrams. The extension fails to sanitize input within WaveDrom fenced code blocks or <script type="WaveDrom"> tags, which are explicitly allowed by the internal sanitizer. An attacker can exploit this by crafting a Markdown file that executes JavaScript within the VS Code webview context. Because the webview lacks a restrictive Content Security Policy (CSP) and the extension's message-passing IPC channel lacks validation, the injected code can trigger internal commands like 'updateMarkdown' to perform arbitrary file writes on the host filesystem. The issue is fixed in version 0.8.28 by migrating to JSON5.parse() and implementing strict JSON sanitization for WaveDrom scripts.
Affected products
- shd101wyy Markdown Preview Enhanced < 0.8.28
Timeline
- 2026-06-02: disclosed: Issue reported on GitHub repository
- 2026-06-05: patched: Version 0.8.28 released
- 2026-06-05: advisory: NVD and VulnCheck advisories published