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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Active

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation poc

Automatable no

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
shd101wyy Markdown Preview Enhanced affected
Version Status Constraints
0 affected < 0.8.28

No data.

No data.

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Project Subscriptions

Vendors Products
Markdown Preview Enhanced Project Subscribe
Markdown Preview Enhanced Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/issues/2315 cve-icon cve-icon cve-icon
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.28 cve-icon cve-icon
https://www.vulncheck.com/advisories/markdown-preview-enhanced-arbitrary-code-execution-via-wavedrom-eval cve-icon cve-icon
History

Fri, 05 Jun 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Fri, 05 Jun 2026 18:15:00 +0000

Type Values Removed Values Added
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.
Title Markdown Preview Enhanced Arbitrary Code Execution via WaveDrom eval()
First Time appeared Markdown Preview Enhanced Project
Markdown Preview Enhanced Project markdown Preview Enhanced
Weaknesses CWE-95
CPEs cpe:2.3:a:markdown_preview_enhanced_project:markdown_preview_enhanced:*:*:*:*:*:*:*:*
Vendors & Products Markdown Preview Enhanced Project
Markdown Preview Enhanced Project markdown Preview Enhanced
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.6, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-06-05T19:03:27.311Z

Reserved: 2026-06-05T16:54:32.159Z

Link: CVE-2026-50733

cve-icon Vulnrichment

Updated: 2026-06-05T19:03:10.502Z

cve-icon NVD

Status : Deferred

Published: 2026-06-05T18:17:34.050

Modified: 2026-06-05T20:17:35.423

Link: CVE-2026-50733

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-05T19:45:03Z

Weaknesses