If your security review fails due to issues with a third-party API that you do not control, here's how you can proceed:
1. **Request Security Reports**: Contact the third-party provider and ask for security reports, such as penetration test results or certifications, to include in your app submission.
2. **Request Updates**: If the issue involves outdated configurations (e.g., TLS 1.0/1.1), ask the provider to update their settings to meet current security standards.
3. **Remove References**: If the provider cannot resolve the issue, consider removing references to the third-party API from your managed package to avoid vulnerabilities.
4. **Document the Issue**: Provide detailed documentation of the issue and your efforts to resolve it. Include this in your submission for transparency.
5. **Open a Case**: Reach out to the security review team, explain the situation, and provide all supporting evidence, including the third-party's response and any mitigations you've implemented.
These steps will help you address the issue and move forward with the security review process.