Microsoft Visual Studio Code mcp.json Command Injection Remote Code Execution Vulnerability (CVE-2026-21518)

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Visual Studio Code.

User interaction is required to exploit this vulnerability in that the target open a malicious project.

The specific flaw exists within the handling of mcp.json files.

The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call.

An attacker can leverage this vulnerability to execute code in the context of the current user.

Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21518

I am one of the editors here at www.systemtek.co.uk I am a UK based technology professional, with an interest in computer security and telecoms.