A vendor assessment is a formal review of a supplier’s security, reliability, privacy, and compliance posture before or during a business relationship. Security teams use it to decide whether a third party is safe to connect to, share data with, or depend on for critical services. The review often covers controls such as access management, encryption, incident response, patching, audit results, and regulatory alignment.
In cyber security, vendor assessments matter because many breaches begin through trusted suppliers rather than direct attacks. Weak remote access, poor software development practices, or unverified compliance claims can turn a partner into an entry point. Defenders use assessments to reduce supply-chain risk, support procurement decisions, and document why a vendor was approved, restricted, or rejected. Good assessments should be evidence-based and repeatable, so that risk labels are clear, defensible, and useful for operational decisions.