To mitigate the potential risks associated with URL schemes in your iOS app, consider:

1. **Use Universal Links:** Universal links allow you to create a two-way association between your app and your website and specify the URLs that your app handles, preventing other apps from hijacking them. 

2. **Validate URL Parameters:** Implement thorough validation checks for all URL parameters received by your app. Ensure that the parameters adhere to expected formats and do not contain any malicious payloads or unexpected data.

3. **Limit Available Actions:** Evaluate the potential impact of each action triggered by a custom URL scheme and restrict access to actions that do not pose a risk to user data or compromise app security. 