A Non-Human Identity Access Review is a formal check of what machine identities can access and whether that access is still needed. It examines service accounts, API keys, tokens, certificates, and agent permissions against current business purpose, ownership, and risk, then identifies excess, stale, or unapproved access for correction.
What Access Review Means for Non-Human Identities
A non-human identity access review is fundamentally a governance check on machine access. The review asks whether a service account, API key, token, certificate, or agent permission still matches a current business need, and whether the access path is still justified by ownership and risk.
Because non-human identities often support automation, integrations, and application-to-application trust, the review is less about who clicked a button and more about whether the system still needs the authority it was granted. That distinction matters when access is embedded in code, pipelines, cloud services, or orchestration layers.
What Gets Reviewed
The scope usually includes the identities and credentials that actually enable machine activity: service accounts, client credentials, API keys, OAuth tokens, certificates, and delegated permissions used by agents or applications. A good review also checks whether the identity is still discoverable, owned, and tied to a named service or business process.
In practice, the most important question is not just whether the credential exists, but whether it is still active for a valid purpose. That is why access review is closely related to lifecycle hygiene, rotation, offboarding, and inventory discipline, as described in NHIMG’s NHI Lifecycle Management Guide.
Why It Matters for Security and Governance
Unreviewed non-human access tends to accumulate quietly, especially in systems that are provisioned once and reused for months or years. Excess permissions, forgotten credentials, and orphaned integrations can expand the attack surface and make later compromise easier to exploit.
Access review is also one of the few practical ways to prove that machine access still follows least privilege. For organisations trying to reduce standing exposure across many credentials and integrations, NHIMG’s Lifecycle Processes for Managing NHIs explains how review fits into the broader control model.
Only 5.7% of organisations have full visibility into their service accounts, which shows why access review is often difficult before it is even complete.
How Access Reviews Are Used in Practice
Teams use access reviews to confirm ownership, validate necessity, and remove stale entitlements before they become silent dependencies. That includes checking whether a token still authenticates a live workload, whether a certificate is still tied to an active service, and whether an agent still needs tool or API access.
Reviewing non-human access also helps distinguish legitimate automation from legacy access that has simply never been cleaned up. NHIMG’s Ultimate Guide to NHIs is useful here because it connects access review to visibility, rotation, offboarding, and Zero Trust thinking.
Risk and Threat Considerations
Non-human access review fails when organisations cannot see all credentials, cannot map them to owners, or treat machine access as permanent by default. That creates long-lived exposure, especially where secrets are embedded in code, exposed to third parties, or left over after a project ends.
Failure mechanism: Excess or stale machine access remains active because no one can confidently prove it is still needed, and attackers or insiders can abuse that standing trust path.
Impact: Compromise of a service account, token, or API key can enable unauthorized access, lateral movement, data exposure, or abuse of automated actions at scale.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 addresses the attack surface, NIST SP 800-53 Rev 5 and CIS Controls v8 set the technical controls, and ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 — Improper Offboarding | Access review checks whether machine access should have been removed. |
| NHI-05 — Overprivileged NHI | The term centers on identifying excess machine access and permissions. | |
| NHI-07 — Long-Lived Secrets | Access reviews often expose credentials that remain valid far longer than intended. | |
| Recommendation — Review and revoke stale non-human access before credentials remain active after business need ends. Reduce standing privilege by recertifying non-human access against current business purpose. Pair access reviews with secret age checks and retire credentials that no longer need to exist. | ||
| NIST SP 800-53 Rev 5 | AC-2 — Account Management | Access review is a core account governance activity for machine identities. |
| IA-5 — Authenticator Management | The review covers authenticators such as API keys, tokens, and certificates. | |
| AC-6 — Least Privilege | The review tests whether machine access is still minimally necessary. | |
| Recommendation — Recertify accounts and disable non-human access that no longer has an approved owner or purpose. Track non-human authenticators through their lifecycle and revoke ones that are stale or unapproved. Tighten machine access to the minimum set of permissions required for the current workload. | ||
| CIS Controls v8 | CIS-5 — Account Management | The subject is a periodic check of accounts and machine access entitlements. |
| CIS-6 — Access Control Management | Access review directly supports control of who or what can reach systems and data. | |
| Recommendation — Inventory non-human accounts and remove access that is no longer justified. Use access reviews to validate and prune non-human permissions across applications and services. | ||
| ISO/IEC 27001:2022 | A.5.16 — Identity management | The review depends on identifying and governing non-human identities and their ownership. |
| A.5.18 — Access rights | The term is specifically about verifying whether access rights remain valid. | |
| Recommendation — Maintain a current inventory of machine identities and their responsible owners. Periodically review machine access rights and withdraw those that are no longer required. | ||
Practitioner Guidance
Governance implication: Treat non-human access review as an ownership problem first and a tooling problem second. If a credential, token, or certificate cannot be tied to a current system owner and business purpose, it should not be considered a valid standing entitlement.
What to watch for: stale integrations, shared credentials, missing ownership, and access paths that survive after the application, pipeline, or agent has changed. NHIMG’s Regulatory and Audit Perspectives is a useful reference when you need to align review evidence with audit expectations.
Related resources from NHI Mgmt Group
- What is the difference between privileged access management and non-human identity governance?
- What is the difference between privileged access and non-human identity governance?
- Why do traditional access reviews miss non-human identity risk?
- How should teams certify non-human identity access without breaking production?
