Linux Server Hardening May 2026

Follow the principle of least privilege to limit what users and services can do.

Linux server hardening is the process of reducing a system's attack surface to protect against unauthorized access and data breaches. A default Linux installation is often a "blank canvas" rather than a fortress; hardening provides the necessary reinforcement. Linux Server Hardening

Run system updates immediately upon setup (e.g., apt update && apt upgrade for Debian/Ubuntu or dnf update for RHEL/Fedora). Follow the principle of least privilege to limit

Configure automatic security updates using tools like unattended-upgrades on Debian/Ubuntu or dnf-automatic on RHEL/Fedora. 2. Secure Access (SSH Hardening) Run system updates immediately upon setup (e

Below is a structured write-up covering the essential stages of a Linux hardening project. 1. Update and Patch Management

Moving SSH from port 22 to a non-standard port can eliminate up to 99% of automated scans. 3. Identity and Access Management

Disable password-based authentication ( PasswordAuthentication no ) in favor of SSH key-pair authentication .