How should organisations evaluate third-party vendors in strategic IT planning?

Why This Matters for Security Teams

Vendor evaluation is really an identity and control problem, not just a procurement task. A third party may introduce service accounts, API keys, certificates, support access, data pipelines, and privileged integrations that outlive the commercial contract. That is why security teams should assess how a vendor affects governance, revocation, monitoring, and blast radius across the full relationship lifecycle. The risk is not hypothetical: the The 52 NHI breaches Report shows that compromised non-human identities are a recurring breach pattern, and OWASP’s OWASP Non-Human Identity Top 10 frames poor governance, overprivilege, and secret handling as core failure modes, not edge cases. In procurement terms, a vendor that is easy to buy can still be hard to contain, hard to audit, and slow to exit. In practice, many security teams discover vendor identity sprawl only after the vendor has already been deeply embedded in production workflows.

How It Works in Practice

A strong vendor review starts by mapping every identity the vendor will need and every identity the vendor may touch. That includes human admin access, machine-to-machine trust, delegated OAuth grants, vault access, and support channels. The evaluation should then test whether those identities can be bounded by least privilege, monitored centrally, and revoked without breaking critical services. Current guidance suggests treating this as a control design exercise, not a questionnaire exercise.

• Ask what secrets, tokens, or certificates the vendor will issue, store, or rotate, and whether they support short-lived credentials.
• Confirm whether access can be tied to roles, scopes, and environment boundaries rather than broad tenant-wide permissions.
• Require logging for authentication, delegation, and administrative actions, with export into your detection stack.
• Validate offboarding: how fast access is removed, how connected secrets are invalidated, and what evidence is returned.

The commercial and technical review should stay aligned. A vendor may pass security review but still fail operationally if it cannot support Shai Hulud npm malware campaign-style supply chain exposure, where one integration point becomes a path to many downstream secrets. That is why the NHI market guidance in Ultimate Guide to NHIs — The NHI Market is useful: the question is not only whether the vendor is secure, but whether its identity model fits your operating model. For implementation discipline, many teams also align review criteria with the OWASP Non-Human Identity Top 10 to check for overprivilege, secret leakage, and weak lifecycle controls. These controls tend to break down when the vendor relies on long-lived shared credentials and opaque support access because revocation becomes incomplete and difficult to prove.

Common Variations and Edge Cases

Tighter vendor control often increases integration overhead, requiring organisations to balance delivery speed against revocation certainty. That tradeoff is real, especially when a vendor supports legacy systems, managed services, or multi-tenant platforms where customer-specific identity boundaries are limited. Best practice is evolving here, and there is no universal standard for how much isolation is enough, so the decision should reflect data sensitivity, privilege level, and exit complexity. A practical distinction is between vendors that merely process data and vendors that can act inside the environment. The latter deserve deeper scrutiny because they may introduce persistent access paths, delegated admin rights, or hidden support backdoors. In higher-risk environments, security teams should insist on documented offboarding procedures, secret rotation obligations, and explicit constraints on sub-processors and support personnel. For broader governance context, Reviewdog GitHub Action supply chain attack illustrates how quickly an integration can expose secrets when trust is too broad, while LiteLLM PyPI package breach reinforces why vendor evaluation must include dependency provenance and secret-handling behaviour. Organisations that handle regulated or highly sensitive workloads should treat vendor identity risk as part of zero trust design, not as a procurement appendix.

Related resources from NHI Mgmt Group

• How do organisations know if third-party monitoring is actually working?
• How can organisations reduce third-party access risk in GRC workflows?
• Why do third-party vendors complicate identity governance more than internal users?
• Should organisations treat AI vendors like third-party suppliers?