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.

Attack Vector Local

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact None

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

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

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 vscode-markdown-preview-enhanced affected
Version Status Constraints
< 0.8.30 affected —

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Project Subscriptions

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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/commit/8bc848b6cbb42b9f35a0f95f7c3bf29b8302970e cve-icon cve-icon
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2323 cve-icon cve-icon
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.30 cve-icon cve-icon
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-82rc-7g3m-2c42 cve-icon cve-icon
History

Wed, 14 Oct 2026 19:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Markdown Preview Enhanced: Arbitrary File Write via updateMarkdown Command Without Path Validation
Weaknesses CWE-73
References
Metrics cvssV4_0

{'score': 5.8, '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-14T19:09:50.323Z

Reserved: 2026-06-15T22:58:06.563Z

Link: CVE-2026-54703

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-14T20:17:47.913

Modified: 2026-10-14T20:17:47.913

Link: CVE-2026-54703

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses