Yes, Coalition has a vulnerability disclosure program, where you can responsibly report security vulnerabilities with Coalition's software and service. Please use https://hackerone.com/coalition to make all reports.
Separately, because we believe that supporting responsible disclosure aids an organization's security, all Coalition policyholders, current and prospective, automatically receive a premium discount during the underwriting of all Coalition policies after activating a security vulnerability disclosure program. To qualify, use the Coalition policyholder app and/or ensure that your program is publicly listed in the HackerOne directory no matter where you operate your program. Read more details in our February 2018 blog post.
Note: Coalition's own program is for the disclosure of software security vulnerabilities only. If you believe your Coalition account has been compromised, change your password and contact firstname.lastname@example.org immediately.