As may have already been brought to your attention, some software mitigation is needed for vulnerabilities dubbed “Meltdown” (CVE-2017-5754) and “Spectre” (CVE-2017-5753, CVE-2017-5715).
If I were to summarize the issue with these vulnerabilities then in principle they would, when successfully exploited, allow reading memory that doesn’t belong to the process, the user or even the same operating system instance. In just that way, the Kolab Now infrastructure isn’t impacted.
However, we’re still going to need to patch this out. The only way we can is by updating software and rebooting systems, and this will happen during the weekend of Saturday January 13th and Sunday January 14th.