Linux Server Hardening May 2026

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

Prevent direct root access by setting PermitRootLogin no in /etc/ssh/sshd_config . Linux Server Hardening

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

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

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.

Securing the primary remote entry point is vital for stopping automated brute-force attacks.