What breaks is coverage. Service accounts, API keys, and other machine identities can retain access long after the operational need has ended, and those identities may never appear in standard employee recertification workflows. The result is privilege creep, poor auditability, and unnecessary exposure in systems that rely on delegated access.
Why This Matters for Security Teams
When identity review programs are designed around employee accounts, they miss the identities that actually do the most machine-to-machine work: service accounts, API keys, workload credentials, and delegated automation. That gap matters because those identities often carry persistent access, are not tied to an HR record, and can survive application changes, team turnover, or even incident response. NHI Mgmt Group’s Ultimate Guide to NHIs notes that only 5.7% of organisations have full visibility into their service accounts, which means most review processes are starting from incomplete inventory rather than true access control. Traditional recertification can therefore produce a false sense of assurance while leaving machine privilege untouched. NIST guidance in NIST SP 800-53 Rev 5 Security and Privacy Controls reinforces that access governance must cover all account types, not just named users. In practice, many security teams discover the blind spot only after a leaked key, an abandoned integration, or an outage caused by an overprivileged service account that no one had reviewed in months.
How It Works in Practice
Employee-centric reviews usually rely on HR-driven attestations, manager approval, and role mapping. That process works reasonably well for people because humans have a known employment status, a manager, and a fairly stable access footprint. Machine identities do not. They are created by pipelines, applications, scripts, and vendors; they may have no direct owner in IAM; and they often authenticate with long-lived secrets that are invisible to standard recertification workflows. The result is an access review that measures job function, not actual runtime privilege.
A more workable approach is to treat non-human identities as first-class assets and review them on their own lifecycle. That means inventorying all service accounts and keys, assigning a technical owner, mapping each identity to a specific workload or integration, and validating whether the credential is still needed for that purpose. Where possible, teams should prefer short-lived credentials, secrets rotation, and workload identity over static shared keys. The Top 10 NHI Issues research highlights why this matters: excessive privilege and poor rotation are common failure modes, and they are rarely caught by employee recertification alone. Current guidance suggests using access review evidence from cloud IAM, secrets managers, CI/CD systems, and application owners together, rather than trusting one directory source.
Operationally, the review should ask whether each machine identity is still active, whether its scope is minimal, whether its secret is rotated on schedule, and whether its owner can prove business need. For example, a database export account may be valid for one deployment job but unnecessary after migration. That identity should be removed or replaced with a time-bound pattern, not left to age silently. These controls tend to break down in environments with ad hoc scripting, unmanaged third-party integrations, or shared credentials embedded in build tooling because ownership and usage are difficult to prove at review time.
Common Variations and Edge Cases
Tighter review coverage often increases operational overhead, requiring organisations to balance stronger assurance against the effort of tracking machine owners, usage context, and expiration dates. The hardest edge case is the identity that is technically “non-human” but embedded in business-critical automation, where immediate revocation could interrupt production. In those cases, best practice is evolving, but the direction is clear: review should drive remediation planning, not just checkbox attestation.
There are also cases where employee and machine identity are mixed, such as a developer using a personal account to create tokens for automation. That pattern can conceal the real control point and should be separated as soon as possible. Another common exception is third-party access, where an external vendor manages the workload but the consuming organisation still owns the exposure. The 52 NHI Breaches Analysis shows that incidents frequently involve credentials that were valid long after their original purpose ended. That is why recertification must expand beyond employee roles to include every identity that can authenticate, authorize, or act on behalf of the business.
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 and CSA MAESTRO address the attack and risk surface, while NIST AI RMF and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 | Identity inventory is required to include service accounts and keys. |
| CSA MAESTRO | IAM-02 | Agentic and machine identities need explicit lifecycle governance beyond HR processes. |
| NIST AI RMF | Governance must cover automated actors that change behavior outside human review cycles. | |
| NIST CSF 2.0 | PR.AC-4 | Least-privilege access reviews should include non-human accounts, not just employees. |
Extend access reviews to every identity type and remove unnecessary entitlements promptly.
