Because they often authenticate successfully but are governed like infrastructure, not identities. That creates standing access paths that are rarely reviewed with the same rigour as human access. Zero Trust only works when non-human identities are subject to the same policy discipline, telemetry, and revocation logic as any other actor.
Why This Matters for Security Teams
Service accounts and workloads complicate zero trust because they rarely behave like people, yet they are often granted durable access and then left out of the review discipline applied to human identities. In a Zero Trust model, the question is not just whether an actor can authenticate, but whether every request is continuously justified, scoped, and revocable. That becomes difficult when automation depends on secrets, certificates, and broad service permissions that persist long after the original need has changed.
This is not a theoretical edge case. NHIMG’s Ultimate Guide to NHIs notes that 90% of IT leaders say properly managing NHIs is essential for a successful zero-trust implementation, while the NIST SP 800-207 Zero Trust Architecture model requires policy decisions to be made on current context, not inherited trust. In practice, many security teams encounter service-account sprawl only after a credential leak, an overprivileged automation job, or an outage forces the issue.
How It Works in Practice
Zero Trust for workloads starts by treating the workload itself as the identity primitive, not the host, subnet, or static secret. Current guidance suggests using workload identity, short-lived credentials, and real-time policy evaluation so access is granted for a specific task and then revoked automatically. The SPIFFE workload identity specification is widely used for this pattern because it gives cryptographic proof of what the workload is, rather than relying on a password or long-lived token.
Operationally, teams should separate three layers:
Identity proof: issue workload identities through a trust domain and attest the runtime environment.
Authorisation: evaluate policy at request time using context such as service, environment, action, and data sensitivity.
Credential lifetime: prefer JIT, ephemeral tokens with tight TTLs and automatic revocation over shared, static secrets.
That model aligns with NIST Zero Trust principles and with NHIMG guidance on lifecycle controls in the Lifecycle Processes for Managing NHIs. It also reduces the risk created by secret storage in code, CI/CD systems, and config files, which NHIMG identifies as a common failure pattern. For service accounts, the practical goal is to remove standing privilege, map each account to an owner, and ensure every credential has a clear expiry, rotation path, and revocation mechanism.
These controls tend to break down in legacy environments where applications cannot refresh tokens cleanly, where batch jobs share accounts, or where identity is still bound to static infrastructure assumptions.
Common Variations and Edge Cases
Tighter workload controls often increase operational overhead, requiring organisations to balance stronger assurance against application compatibility and release speed. Best practice is evolving, and there is no universal standard for every platform, especially in environments with mainframes, embedded systems, or third-party integrations that were never designed for ephemeral identity.
One common exception is monitoring or backup software that needs broad read access across many systems. Even there, the access should be narrowly scoped, time-bound, and separately governed rather than treated as a permanent exception. Another edge case is Kubernetes, where service accounts may be numerous and automatically created; without strong namespace boundaries and token projection settings, these accounts become a major source of implicit trust.
NHIMG’s Top 10 NHI Issues and 52 NHI Breaches Analysis both show that overprivilege, missing ownership, and weak rotation are recurring themes. For teams building Zero Trust programmes, the key decision is not whether workloads need access, but whether that access can be continuously justified under policy. If it cannot, the programme is still depending on standing trust, just under a different label.
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-03 | Addresses weak lifecycle control and rotation for service-account credentials. |
| NIST CSF 2.0 | PR.AC-4 | Covers access enforcement for identities based on policy and context. |
| NIST AI RMF | Supports governing autonomous policy decisions and identity risk in dynamic systems. |
Define ownership, monitoring, and escalation paths for workload identities under the AI RMF governance function.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on June 7, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
