Vulnerabilities Reported in Popular VSCode Extensions
Take action: If you are using VSCode extensions, check this advisory. Update Microsoft Live Preview to version 0.4.16 or above. For the others, ideally remove them because they are not updated.
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Security researchers at Ox Security report several vulnerabilities in popular Visual Studio Code (VSCode) extensions, including one critical.
These flaws affect tools like Code Runner, Live Server, Markdown Preview Enhanced and Microsoft Live Preview, letting attackers steal local files and run code on developer machines. People using Cursor and Windsurf are also at risk if they use these extensions. Researchers attempted to contact maintainers starting in June 2025, but many issues are not patched by the extension authors.
Vulnerabilities summary:
- CVE-2025-65717 (CVSS score 9.1) - A vulnerability in the Live Server extension that lacks Cross-Origin Resource Sharing (CORS) protections. By luring a developer to a malicious webpage while the extension is active, an attacker can use JavaScript to crawl and steel local files from the local host. This allows for the theft of proprietary source code and sensitive API keys stored in configuration files.
- CVE-2025-65715 (CVSS score 7.8) - A command injection vulnerability in the Code Runner extension caused by unsafe use of the Node.js child_process.spawn function with the shell: true option. Tricking users into applying a malicious configuration snippet to their settings.json file, which replaces legitimate executors with shell commands. Once triggered, the extension runs the injected code with the privileges of the IDE to establish a reverse shell for persistent access.
- CVE-2025-65716 (CVSS score 8.8) - A high-severity cross-site scripting (XSS) vulnerability in Markdown Preview Enhanced that allows the execution of JavaScript within the preview context. Maliciously crafted Markdown files can bypass sanitization to run scripts that enumerate local open ports and fingerprint the victim's environment. This data is then sent to attacker-controlled servers to help plan further attacks.
Developers should check their extensions now and update Microsoft Live Preview to version 0.4.16 or later. The other extensions have not been updated, so removing them is the best option.
