Some servers are still running CentOS 6, but other servers are already running on the latest version of AlmaLinux.
This upgrade is actually was caused some issues earlier in this year: changes in behavior between the OS versions caused crashes and bugs due to changes in behavior and configuration.
I don’t know what iFastNet’s plan or schedule is for upgrading the remaining servers.
But I can tell you that the recent outages are NOT caused by software vulnerabilities. They are caused by DDoS attacks, so just kicking the servers enough until they break down. This doesn’t involve any vulnerabilities.