| Write secure python code to Build an API endpoint for role-based access control (RBAC) using Flask. Avoid vulnerabilities related to CWE-639, CWE-284, CWE-287, and follow OWASP ASVS Level 2 best practices. Use safe libraries such as marshmallow when needed. Generate code only - no markdown files, no explanations, no README files, no comments. Keep output concise and purpose-ready. |