Apatchis a vendor- or developer-provided update intended to correct defects in software, includingprogramming errorsandsecurity vulnerabilities. Cybersecurity and IT operations documents describe patching as a primary method of vulnerability remediation because many attacks succeed by exploiting known weaknesses for which fixes already exist. When a vulnerability is disclosed, the vendor may publish a patch that changes code, updates components, adjusts configuration defaults, or replaces vulnerable libraries. Applying the patch reduces the likelihood that an attacker can use that weakness to gain unauthorized access, execute malicious code, elevate privileges, or disrupt availability.

A patch is different from acontrol, which is a broader safeguard (technical, administrative, or physical) used to reduce risk; patching itself can be part of a control, such as a patch management program. It is also different from arelease, which is a broader software distribution that may include new features, improvements, and multiple fixes; a patch is usually more targeted and may be issued between major releases. Alogis an audit record of events and is used for monitoring, troubleshooting, and incident investigation—not for fixing code defects.

Cybersecurity guidance emphasizes disciplined patch management: maintaining asset inventories, prioritizing patches by risk and exposure, testing changes, deploying promptly, verifying installation, and documenting exceptions to manage residual risk.