CVE-2026-50733 — HIGH (8.8)

Vulnerability 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.

CVSS Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Related Weaknesses (CWE)

CWE-95

References

FAQ

What is CVE-2026-50733?

CVE-2026-50733 is a vulnerability with a CVSS score of 8.8 (HIGH). 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...

How severe is CVE-2026-50733?

CVE-2026-50733 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-50733?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.