OAuth scopes define what a token can do and where it can go. Without tight control, they become a wide-open gate inside your application. Poor scopes management means over-privileged tokens, silent data leaks, and attack paths you will not see until they are exploited. The fix is clear: restrict access at the scope level.
Scope restriction starts with least privilege. Assign scopes based only on the operations the client must perform. Avoid broad, catch-all scopes unless absolutely necessary. Break down permissions into granular, task-specific scopes. This keeps token power narrow and contained.
Inventory every scope in your system. Map them to the APIs and resources they unlock. Then audit current tokens to see which scopes they actually use. Remove unused scopes. Delete old tokens with dangerous access. Version your scope lists so changes are tracked and reviewed.