There is 1 open security issue in bullseye.
1 issue left for the package maintainer to handle:
KDE KCron through 21.12.2 uses a temporary file in /tmp when saving, but reuses the filename during an editing session. Thus, someone watching it be created the first time could potentially intercept the file the following time, enabling that person to run unauthorized commands.
You can find information about how to handle this issue in the security team's documentation.