CVE-2026-54703

5.8 MEDIUM 0.3% exploit odds Fix listed Other

What it is

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.

At a glance

Exploitability: Can be exploited locally on the machine without logging in, but needs a user to act. High risk of data tampering, service disruption.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-10-14 20:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-16 20:02 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 5.8 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-10-14 20:17 UTC
Last modified: 2026-10-16 20:02 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-73
Record status: Awaiting Analysis

Attack profile CVSS 4.0 · 5.8

Attack vector: Local
Complexity: Low
Attack requirements: Present
Privileges needed: None
User interaction: Passive
Confidentiality: None
Integrity: High
Availability: High

Raw 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/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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-54703.md and follow it. Check whether this project is affected by CVE-2026-54703. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record