How to Check Your MCP Server for CVE-2026-5603's Vulnerability Pattern (And Why shellQuote Isn't Enough)

CVE-2026-5603 is a Critical command injection in @elgentos/magento2-dev-mcp , but the vulnerability pattern it represents shows up in community MCP servers regularly. This post explains what the vulnerability is, why the sanitizer fails on Windows, how to check your own MCP server code for the same issue, and what the correct fix looks like. What Is CVE-2026-5603? @elgentos/magento2-dev-mcp is an NPM package that exposes Magento 2 development operations as MCP tools: database queries, cache mana