Linux servers already have package managers. For most admins, that creates an assumption that patching is largely solved. Run updates, reboot when needed, move on. In small environments, that can feel true for a long time. Then the environment grows, security advisories start landing more often, and someone asks a simple question you cannot answer cleanly: Which systems are actually patched right now?

Source: Best Open-Source Linux Patch Management Software for Secure Linux Servers