On request the sdbootutil script creates a world-readable debug log in /var/log/sdbootutil.log. The log file is created world-readable, however, which means that arbitrary low-privileged users in the system will be able to extract secrets from it.
There are two invocations of qrencode to display a QR code for scanning. These invocations leak the private data $pin / $key via /proc accessible for arbitrary low-privileged users in the system.