Manual reviews break when reviewers cannot reliably see all active entitlements across cloud, on-prem, and third-party systems. The result is incomplete certification, stale access that survives role changes, and weak remediation evidence. In practice, the review process becomes too slow to reflect how quickly modern permissions drift.
Why This Matters for Security Teams
Manual access reviews are usually built around a human reviewer looking at a point-in-time export, but hybrid environments do not behave like point-in-time systems. Entitlements span cloud IAM, on-prem directories, SaaS admin consoles, CI/CD tooling, and service accounts that may never appear in the same report. That makes the review problem less about policy intent and more about inventory integrity, evidence quality, and remediation speed.
This is especially risky for non-human identities because the blast radius is often larger than the account count suggests. NHI Mgmt Group notes that NHIs outnumber human identities by 25x to 50x in modern enterprises, and only 5.7% of organisations have full visibility into their service accounts, according to the Ultimate Guide to NHIs. When reviewers cannot see the full entitlement graph, certifications can falsely confirm access that should have been removed.
In practice, many security teams encounter toxic entitlement drift only after an audit exception, an incident, or a failed offboarding event rather than through intentional review hygiene.
How It Works in Practice
Manual reviews break down because hybrid access is not a single control plane. A practical review must aggregate identities, roles, group memberships, token grants, app-specific permissions, and privileged pathways across environments before a manager or application owner can make a decision. The usual failure is not lack of effort, but lack of authoritative context. Without that context, reviewers approve access that looks legitimate in one system while missing conflicting or dormant access in another.
Current guidance suggests moving toward continuous or event-triggered certification where the access review is fed by current entitlements, not a spreadsheet export. In NHI-heavy environments, that means pairing identity governance with secrets inventory, service account discovery, and change signals from HR, PAM, and cloud control planes. The NHI Lifecycle Management Guide is useful here because lifecycle state is what turns a review from an approval exercise into a control over stale access.
- Synchronise identity sources so reviewers see one current entitlement record per user or workload.
- Flag privileged, dormant, and third-party access separately so risky items are not buried in bulk recertification.
- Require evidence of removal, not just approval, for revoked access.
- Use policy checks to detect access that no longer matches role, contract, or system ownership.
For broader risk context, the OWASP Non-Human Identity Top 10 is a strong reference point because manual review gaps often overlap with excessive privilege, credential sprawl, and poor lifecycle control. These controls tend to break down when entitlements are minted and consumed inside ephemeral CI/CD pipelines because the access exists for too little time, and across too many systems, for a reviewer to certify accurately by hand.
Common Variations and Edge Cases
Tighter certification often increases operational overhead, requiring organisations to balance review accuracy against cycle time and reviewer fatigue. That tradeoff becomes sharper in hybrid environments where not every platform exposes the same metadata, and not every entitlement is tied cleanly to a named person. Best practice is evolving for these cases, especially where shared service accounts, delegated admin roles, and third-party support access are involved.
There is no universal standard for this yet, but current guidance suggests separating human access reviews from NHI and machine access governance. A reviewer should not be asked to certify a cloud role, an API key, and a privileged service account in the same workflow if the underlying evidence model is different. The 52 NHI Breaches Analysis illustrates why this matters: weak visibility and delayed revocation repeatedly show up as root causes, not just contributing factors.
For programme owners, the practical test is simple: if a reviewer cannot prove what existed at the start of the campaign and what changed before closure, the review is descriptive rather than preventive. That is often acceptable for low-risk entitlements, but it is not adequate for privileged, third-party, or long-lived access in regulated hybrid estates.
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 |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 | Hybrid reviews fail when NHI inventory and visibility are incomplete. |
| NIST CSF 2.0 | PR.AA-01 | Access control depends on knowing who or what has current permissions. |
| NIST AI RMF | Governance must ensure accountability and traceable decisions in dynamic systems. |
Use governance processes that tie access decisions to current risk and evidence.
