Just a quick question for the ones that run Debian 9/Stretch. The recent 9.5 Release came with quite few udpates and some of the more important updates are: apache (apache2 apache2-bin apache2-data apache2-doc apache2-suexec-pristine apache2-utils) clamav/clamav-freshclam (clamav clamav-base clamav-daemon clamav-docs clamav-freshclam clamdscan, libclamav7) And of course the linux-image-amd64 is kept back. My concern is if apache needs re-configuring or there are major 'diff' between new or old that might break ISPCONFIG3. Same goes for Clam, the other I am not concern about because there are over a dozen updates. Source: Debian News 7/14/18
There should be no issues with installing the apache update. The ClamAV update might require it that you remove some options from clamd.conf (the Stats' lines, just comment them out if they exist in that file). Nonetheless, you should install all updates. I would also install the linux-image-amd64 update that has been kept back.