How do organisations reduce risk from third-party machine identities?

They should treat supplier-connected credentials as part of the same identity governance model as internal NHIs. That means limiting access to the minimum required, rotating secrets, reviewing logs, and confirming that the vendor relationship still justifies the access. Supplier access is only low risk when it is actively governed.

Why This Matters for Security Teams

Third-party machine identities are often created for the fastest path to integration, not for durable governance. That is where risk accumulates: supplier service accounts, API keys, certificates, and CI/CD tokens can outlive the contract, exceed the intended scope, or remain hidden in code and automation. NHI Management Group research shows that 92% of organisations expose NHIs to third parties, and only 5.7% have full visibility into service accounts, which makes supplier access hard to govern once it is granted.

The practical issue is not just initial trust, but continuous validation. A vendor that once needed read-only access may later gain write access, broader network reach, or persistent secrets that are never revisited. Current guidance from OWASP Non-Human Identity Top 10 and NIST Cybersecurity Framework 2.0 both point toward least privilege, continuous monitoring, and lifecycle control rather than one-time setup.

In practice, many security teams discover supplier credential sprawl only after an incident review reveals dormant access that was never formally owned.

How It Works in Practice

Reducing risk from third-party machine identities starts by treating them as governed assets, not as temporary exceptions. Each supplier credential should have an owner, a documented purpose, an expiry date, and a revocation path tied to the contract or service ticket. Where possible, prefer workload identity and federated trust over long-lived shared secrets, because it reduces the number of static credentials that can be stolen, copied, or forgotten.

A workable control set usually includes scoped RBAC or policy-based access, secret rotation, log review, and periodic re-authorisation. That means confirming whether the vendor still needs access, whether the permissions still match the task, and whether the credential has been used outside expected patterns. The The 52 NHI breaches Report and Top 10 NHI Issues both reinforce the same operational lesson: secrets and service accounts are frequently compromised because they are over-permissioned and under-monitored.

• Issue credentials per supplier use case, not per organisation-wide relationship.
• Use JIT where the integration supports it, and revoke access automatically when the task ends.
• Separate human vendor administrators from the machine identities they manage.
• Log authentication, secret use, privilege changes, and failed access attempts.
• Reassess access when the vendor’s scope, staff, or tooling changes.

For implementation detail, the safest path is usually a federation model that aligns with the Ultimate Guide to NHIs — Key Challenges and Risks and the identity governance expectations in NIST Cybersecurity Framework 2.0. These controls tend to break down when vendors embed static credentials in scripts, because the organisation loses visibility into where the secret lives and who can still use it.

Common Variations and Edge Cases

Tighter supplier control often increases integration overhead, requiring organisations to balance speed of onboarding against the cost of more frequent reviews and reissuance. That tradeoff is real, especially when a vendor supports legacy systems, managed services, or always-on infrastructure where short-lived credentials are not easy to implement.

Best practice is evolving for these cases. There is no universal standard for every supplier scenario, but the direction is clear: reduce standing privilege, shorten secret lifetime, and prefer monitored federation over copied credentials. For high-trust partners, risk can be lowered without blocking operations by using limited blast-radius accounts, network segmentation, and explicit approval for any elevation.

Edge cases also appear when suppliers subcontract parts of their service. In those environments, the original risk assessment may no longer reflect the actual operator of the machine identity, which is why contract reviews and access recertification matter as much as technical controls. The Shai Hulud npm malware campaign and Reviewdog GitHub Action supply chain attack show how third-party tooling can turn trusted automation into a secrets exposure path.

In environments with heavy automation, multiple tenants, or shared CI/CD runners, supplier machine identities often break the usual review cadence because access is distributed across platforms faster than governance teams can reconcile it.

Related resources from NHI Mgmt Group

• How can organisations reduce the blast radius of compromised agent identities?
• How can organisations reduce risk from third-party OAuth integrations?
• Why do non-human identities create more audit risk than human accounts?
• Why do non-human identities create audit risk in modern environments?