Patch management covers the entire process from identifying available security updates through testing to deploying them on all affected systems. Structured patch management is one of the most effective defenses against cyberattacks, since a large share of successful attacks exploit known, already-patched vulnerabilities. ISO 27001 Annex A.8.8 requires technical vulnerability management. Your patch process should define timelines (e.g., critical patches within 72 hours), describe testing procedures, and include an exception process for systems that cannot be patched immediately. Maintain a current overview of the patch status across all systems.