Markdown Preview Enhanced: Arbitrary File Write via updateMarkdown Command Without Path Validation
CVSS score
5.8
EPSS probability
—
Risk score
0.6
Published
4 h ago
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Impact on My Inventory
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Vulnerability description
CVE AI research
DayBreach AI Explanation
Verified against sourcesSources read
1
Source agreement
Tam uyum
Evidence confidence
%55
Short explanation
Versions of Markdown Preview Enhanced prior to 0.8.30 contain an arbitrary file write vulnerability due to the lack of path validation in the updateMarkdown command.
This vulnerability allows attackers to modify arbitrary files under user permissions via pre-executed JavaScript.
What should be done?
- Upgrade the software to the fixed version
- Follow vendor advisories
- Apply additional validation controls
Chain of evidence and sources
Markdown Preview Enhanced eklentisinin 0.8.30 öncesi sürümleri updateMarkdown komutunda yol doğrulaması yapmamaktadır.
Zafiyet, önizleme webview ortamında çalışan JavaScript kodunun eklenti mesaj köprüsünü kullanarak dosya yazmasına olanak tanır.
Show the technical text from the sources
Markdown Preview Enhanced is a Markdown preview extension for Visual Studio Code. Prior to 0.8.30, the _crossnote.updateMarkdown command in Markdown Preview Enhanced accepts an arbitrary URI and attacker-controlled content, then passes them to vscode.workspace.fs.writeFile without validating that the target is the Markdown file represented by the current preview. JavaScript already executing in the preview webview can invoke this command through the extension message bridge and write any file permitted by the VS Code user's operating-system privileges, including user configuration, startup, source, and build files. This file-write vulnerability requires a separate webview JavaScript execution path, such as the independently tracked head.html injection and blind command-dispatch weaknesses. This issue is fixed in version 0.8.30.
CVSS vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
CWE: CWE-73
Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-54703 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | shd101wyy | vscode-markdown-preview-enhanced | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 5.8 | CVSS V40 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD |
| 5.8 | CVSS V4_0 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N | CVE CNA |
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-54703 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-54703 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
CVSS Vector Radar Chart
5.8 / 10Vulnerability Scoring Details
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:NYama durumu bilinmiyor
Weakness Type (CWE & CAPEC)
Similar Vulnerabilities
Markdown Preview Enhanced: One Click RCE via Markdown Link Command Injection on Windows
Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`
Markdown Preview Enhanced: Blind Command Dispatch via Unvalidated Webview Message Handler
Markdown Preview Enhanced: Stored XSS via Unsanitized `.crossnote/head.html` Injection in Webview
Get this vulnerability through the API
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curl -H "x-api-key: $DAYBREACH_API_KEY" \ "https://api.daybreach.dev/api/v1/intel/cves/CVE-2026-54703"