The correct thing to do is either not use the library, or to restrict usage by never pass arbitrary user-controllable data to it. Whitelisting would definitely

The correct thing to do is either not use the library, or to restrict usage by never pass arbitrary user-controllable data to it. Whitelisting would definitely work, as long as the whitelist cannot be externally manipulated. Don't expose the whitelist rather than relying on Object.Freeze.