MCP Security and Authentication
Add authentication to your MCP server using OAuth 2.0 tokens, implement input validation to prevent injection attacks, and apply the principle of least privilege to tool permissions.
Why MCP Security Matters
An MCP server is a gateway into your systems. Without proper security, a compromised AI client or malicious prompt could read sensitive data, trigger destructive operations, or exfiltrate information through the tool call channel. Security for MCP servers must be defense in depth: authentication at the transport layer, authorization at the tool level, and input validation on every call.
Local vs. Remote Server Security
The stdio transport (used by Claude Desktop) has inherent security: the server runs as a local process, only accessible to the user who launched it. Network-exposed MCP servers using HTTP/SSE face the full range of web security threats: authentication bypass, injection attacks, and unauthorized access. Security requirements differ dramatically based on deployment mode.
- Local stdio: Trust the local user; focus on input validation
- Remote HTTP/SSE: Full authentication, TLS, rate limiting, input sanitization
All lessons in this course
- What Is MCP and Why It Matters
- Building Your First MCP Server
- Exposing Database Resources via MCP
- MCP Security and Authentication