Non-human identities often have broader, longer-lived access than people, and their permissions can be hard to see in periodic reviews. If the identity is not being used as expected, a certification process may still approve it. Continuous usage analysis is needed to find stale or excessive access.
Why Access Reviews Miss NHI Risk
Access reviews are built to confirm whether a named identity still needs its role, but non-human identities rarely behave like employees with stable job functions. Service accounts, API keys, bots, and machine credentials can be over-permissioned, long-lived, and used only during narrow system events, which makes periodic certification a weak signal. NHI Mgmt Group research shows that 97% of NHIs carry excessive privileges, so a review may approve access that is far broader than the workload actually requires. See the Ultimate Guide to NHIs and the companion analysis on Ultimate Guide to NHIs — Key Challenges and Risks.
The core problem is visibility. Reviewers may see a valid owner, a valid ticket, and a valid entitlement, yet still miss that the identity has not been used for months, has inherited permissions through a group, or is shared across pipelines. That is why periodic access certification alone does not answer whether access is safe, only whether it was documented. Current guidance from the OWASP Non-Human Identity Top 10 and NHI governance practice points toward continuous validation, not one-time approval. In practice, many security teams encounter NHI overexposure only after a secret leak, a vendor compromise, or a stale automation account has already been used for lateral movement.
How Effective Reviews Need to Change
Effective NHI review programs need to shift from asking who approved the identity to asking what the identity actually does, when it does it, and whether that use still matches the current workload. That usually means combining entitlement review with runtime telemetry, secret inventory, rotation status, and ownership data. If an API key is active but unused, or a workload token is being consumed from an unexpected host, the issue is no longer just access governance, it is a control failure across lifecycle and monitoring.
Practitioners should treat this as a layered control problem:
- Inventory every NHI, including service accounts, CI/CD tokens, certificates, and agent credentials.
- Map each identity to a workload owner and an approved purpose.
- Check whether the access is still needed at the current privilege level.
- Use usage analytics to detect stale, shared, or dormant credentials.
- Rotate or revoke secrets that outlive their task or drift from their intended scope.
This is where the NHI Lifecycle Management Guide becomes useful, because access review is only one checkpoint in a broader lifecycle discipline. For a breach-driven view of how often machine identities are the weak link, the 52 NHI Breaches Analysis helps show the pattern. When paired with the OWASP guidance, the operational answer is to make reviews evidence-based, not paperwork-based. These controls tend to break down in environments with unmanaged shadow automation, shared credentials, or secrets embedded directly in code because there is no reliable source of truth for review.
Where the Review Model Breaks Down
Tighter review processes often increase operational overhead, requiring organisations to balance assurance against speed and automation. That tradeoff becomes more pronounced when workloads are ephemeral, highly distributed, or owned by multiple teams. In these cases, a reviewer may not be able to judge whether access is appropriate without runtime context, and there is no universal standard for how much historical usage is enough to justify continued access.
Edge cases are common in CI/CD, cloud-native platforms, and agentic systems. A deployment token may be valid only for a few minutes, a certificate may authenticate a workload across many clusters, or an autonomous agent may chain tools in ways no human reviewer predicted. For that reason, best practice is evolving toward context-aware checks, shorter credential lifetimes, and stronger workload identity signals rather than relying on calendar-based certification alone. The OWASP Non-Human Identity Top 10 and NHI research both reinforce that long-lived secrets and weak ownership models make reviews look complete while leaving real exposure untouched. A common pattern is that the review says “approved,” but the actual workload has already changed, and the access has become stale before the next cycle starts.
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 address the attack and risk surface, while NIST CSF 2.0 and NIST Zero Trust (SP 800-207) set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 | Addresses missing visibility and overprivileged machine identities. |
| NIST CSF 2.0 | PR.AC-4 | Least-privilege access reviews need ongoing entitlement validation. |
| NIST Zero Trust (SP 800-207) | Zero Trust requires continuous verification, not periodic trust in credentials. |
Inventory NHIs continuously and verify each entitlement against current workload need.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on May 26, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
