Patch is a software, firmware, or configuration update that fixes a defect, including a vulnerability an attacker could use to gain access, execute code, escalate privileges, or expose data. Patching reduces the exploitable attack surface across operating systems, applications, network devices, and embedded systems; it does not remove risk from unsupported or misconfigured assets, and updates can sometimes introduce compatibility or availability problems.
Effective patch management starts with an accurate inventory and vulnerability assessment, then prioritizes internet-facing systems, high-impact assets, and flaws known to be exploited. Organizations should test updates where practical, deploy them within defined time limits, verify installation, and retain rollback or compensating controls when immediate patching is unsafe. Monitoring vendor advisories and threat intelligence can identify urgent fixes, while documenting exceptions and coverage supports vulnerability management and audit requirements.