The WordPress REST API is fundamental for creating decoupled (headless) websites, but it introduces specific security challenges. Unlike traditional WordPress, the API endpoints expose data that must be protected. Standard authentication methods include OAuth 1.0a, Application Passwords (for server-to-server communication), and Nonces (for authenticated requests from the front end). Proper sanitization and validation of all incoming data are non-negotiable. Furthermore, limiting API access via firewalls and ensuring HTTPS is enforced across all requests are crucial steps to prevent unauthorized access and data breaches in a headless environment.