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Third-Party Cyber Risk / Ongoing assurance
Third-party cyber risk guide

Ongoing Third-Party Cyber Assurance

What should ongoing third-party cybersecurity monitoring include after onboarding?

Direct answer

Monitor the conditions that could change the risk decision: evidence freshness, unresolved findings, significant incidents, material service or ownership changes, privileged-access changes, resilience issues, contractual exceptions and remediation commitments. Review frequency should reflect vendor criticality and event triggers, not a fixed annual questionnaire alone.

External reference

National Institute of Standards and Technology (NIST) — SP 800-161 Rev. 1 — Cybersecurity Supply Chain Risk Management Practices for Systems and Organizations

NIST C-SCRM guidance treats supplier and product/service risk as part of ongoing enterprise risk management rather than a one-time procurement activity.

Primary source →

Practical workflow

Step 1

Define review triggers

Use time-based reviews plus incident, ownership, architecture, contract, evidence-expiry and major-service-change triggers.

Step 2

Track evidence freshness

Record what evidence supports the current decision, when it was reviewed, what scope it covers and when it should be refreshed.

Step 3

Track findings and commitments

Keep findings, exceptions, remediation owners, due dates and accepted residual risk connected to the vendor record.

Step 4

Monitor operational signals

Connect incidents, integration health, outages or material security events to the vendor and affected business dependency where possible.

Step 5

Reassess the decision

Escalate when evidence, incidents or changes invalidate the assumptions used during onboarding or the last review.

Relevant Cybatar sources

Claim boundary

Continuous assurance does not mean continuous surveillance or guaranteed visibility into a supplier. Monitoring depends on available evidence, contractual rights, technical signals, disclosed changes and the organisation’s own review process.

These pages are Cybatar-authored third-party cyber risk and resilience guidance. NIST publications are used as external references. The mappings are not NIST validations, certifications, endorsements, legal opinions or statements that a supplier or deployment is secure.

Evidence