We publish the information related to security issues here:
There, we add instructions in order to solve the security issue.
Bitnami will publish a new solution each time a security update is released in some of its components.
If you detect that your system is affected by some security update (https://security-tracker.debian.org/tracker/ could be a good starting point for Debian) you can update the specific package (if the issue is related to system packages) or follow this guide to migrate your WordPress to a newer instance.
I hope it helps