Manual or incomplete access reviews create a documentation gap that can fail both security and certification objectives. Reviewers may approve entitlements they cannot validate, removed access may remain active, and the organisation may be unable to prove control ownership to an assessor. That turns identity governance into a compliance liability rather than a control.
Why This Matters for Security Teams
Manual CMMC access reviews fail when reviewers are asked to approve access they cannot actually verify. That creates two problems at once: the control no longer demonstrates least privilege, and the evidence trail becomes too weak for an assessor to trust. In identity-heavy environments, this is not just an administrative miss. It is a sign that access ownership, entitlement accuracy, and revocation discipline are out of sync.
NHIMG research shows the scale of the problem in non-human access governance, where only 5.7% of organisations have full visibility into their service accounts, and 97% of NHIs carry excessive privileges in many environments, according to the Ultimate Guide to NHIs. While CMMC is not an NHI-specific framework, the same failure mode appears in human and machine identities alike: if the review is based on stale exports, ownership assumptions, or spreadsheet sign-off, the organisation is validating paperwork instead of access.
Security teams also underestimate how quickly incomplete reviews become a certification issue. A reviewer who cannot confirm whether an entitlement is still needed may approve it “for continuity,” especially when application owners are unavailable. In practice, many security teams encounter control failure only after an assessor asks for proof that removed access was actually removed, rather than through intentional governance checks.
How It Works in Practice
A defensible access review process starts with an authoritative entitlement source, a named control owner, and a defined review cadence. For CMMC, the goal is not simply to collect signatures. The goal is to show that every privileged or sensitive access path was examined against current business need, and that any unnecessary access was removed promptly. The OWASP Non-Human Identity Top 10 is useful here because it highlights the risks of excessive standing privilege and poor lifecycle control, which often mirror the same issues found in manual review programs.
Practical controls usually include:
- Exporting access from a system of record rather than from ad hoc spreadsheets.
- Requiring each entitlement to have a business owner, technical owner, and current justification.
- Removing dormant, orphaned, or unassigned access before the review begins.
- Capturing evidence that ties each approval or revocation to a specific identity, system, and date.
- Escalating unresolved items instead of auto-approving them by default.
For machine identities, the same discipline should extend to service accounts, API keys, certificates, and automation tokens, especially where the NHI Lifecycle Management Guide shows that offboarding and rotation are often weak points. CMMC assessors do not need perfection, but they do need traceability, repeatability, and evidence that review findings changed the environment rather than being archived as paperwork. These controls tend to break down when identity data is fragmented across HR, IT, cloud, and application teams because no single owner can validate what is actually in scope.
Common Variations and Edge Cases
Tighter review controls often increase operational overhead, requiring organisations to balance auditability against reviewer burden. That tradeoff is especially visible in hybrid environments, where human users, contractors, service accounts, and cloud roles are reviewed under different ownership models. Current guidance suggests that one review format rarely fits all identities, and trying to force a single spreadsheet process across all systems usually increases errors instead of reducing them.
There is also a genuine edge case when access is technically necessary but business ownership is unclear. In those situations, best practice is evolving, but the safer approach is to quarantine the entitlement, assign interim ownership, and document the exception rather than silently re-approve it. The broader lesson from the 52 NHI Breaches Analysis is that unclear ownership and delayed revocation often matter more than the initial grant.
Manual reviews fail fastest in large distributed environments with many delegated approvers, because approvers often lack context for the systems they sign off on. Where that is the case, organisations should move toward evidence-backed review packets, automated entitlement reconciliation, and exception handling that is time-bound, tracked, and revalidated. A review that cannot prove revocation is only a snapshot, not a control.
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 AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | PR.AA-01 | Manual reviews fail when identity access cannot be validated and tracked. |
| OWASP Non-Human Identity Top 10 | NHI-03 | Excessive standing access is a core risk when reviews are incomplete. |
| NIST AI RMF | Governance and traceability are required when automated and human access decisions are changing. |
Establish accountable, repeatable review governance with evidence retention and exception handling.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on June 11, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
