CVE-2026-50733
Markdown Preview Enhanced Arbitrary Code Execution via WaveDrom eval()
- State
- Published
- Severity
- 8.6 High
- Published
- Jun 5, 2026
- Updated
- Jun 5, 2026
- Reserved
- Jun 5, 2026
Description
Markdown Preview Enhanced before 0.8.28 parses WaveDrom diagrams by evaluating untrusted markdown content with eval(), allowing arbitrary JavaScript execution. The flaw affects every render path - the live preview (window.eval) and presentation mode plus HTML export (the bundled WaveDrom.ProcessAll()/eva() helpers) - and can also be triggered through a <script type="WaveDrom"> element injected via raw HTML in markdown. When a victim previews or exports a crafted markdown document, an attacker can execute arbitrary code, leading to arbitrary file write. Fixed in 0.8.28 by parsing with JSON5.parse() and sanitizing WaveDrom data scripts to inert strict JSON.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.6 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-95 Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
Affected Products
| Product | Versions |
|---|---|
Markdown Preview Enhancedshd101wyy |
|
References
- Release 0.8.28release-notes
- Issue #2315issue-tracking
- VulnCheck Advisory: Markdown Preview Enhanced Arbitrary Code Execution via WaveDrom eval()third-party-advisory
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