CVE-2026-50733
highpriority · track · 0EPSS 0.007 · 52 %ileEUEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.1–8.8
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (1)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/issues/2315cnnvd
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releasesPatchcnnvd
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.28cnnvd
- https://www.vulncheck.com/advisories/markdown-preview-enhanced-arbitrary-code-execution-via-wavedrom-evalcnnvd
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/issues/2315enisa_euvd
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.28enisa_euvd
- https://www.vulncheck.com/advisories/markdown-preview-enhanced-arbitrary-code-execution-via-wavedrom-evalenisa_euvd
- https://github.com/shd101wyy/vscode-markdown-preview-enhanced/issues/2315nvd
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