Open Source Patch Management
Patch management is the unglamorous layer that quietly decides how exposed you are - the gap between a fix shipping and it reaching every machine is exactly the window attackers live in, and most breaches exploit holes that were already patched somewhere else. The open source options below give you visibility into what's installed and what's missing across your fleet without phoning that inventory home, and run on infrastructure you control, so the system tracking your vulnerabilities isn't itself an outside dependency.

Fleet
Open MDM platform for managing, updating, and securing devices across every OS

PatchMon
Track pending updates and CVEs across a Linux fleet, then approve and run patches from one dashboard

Foreman
Manage the full server lifecycle: provision bare metal, VMs, and cloud, then patch and configure from one place

Uyuni
Patch, configure, and provision thousands of Linux servers across data center, edge, and cloud from one console