The uncontrolled growth of non-human identities such as service accounts, API keys, OAuth clients, and machine roles. It becomes a governance problem when ownership, purpose, rotation, and decommissioning are unclear, leaving dormant credentials active long after their original use case ends.
Expanded Definition
NHI sprawl describes the accumulation of service accounts, API keys, OAuth clients, workload identities, and machine roles faster than security teams can assign owners, define purpose, or retire them. In practice, it is a lifecycle and governance failure, not just an inventory problem. The term overlaps with secret sprawl, but NHI sprawl is broader because the identity itself, its permissions, and the secrets attached to it can all multiply across systems. Definitions vary across vendors, but the operational meaning is consistent: too many machine identities exist with too little accountability. That is why NHI sprawl is best understood through lifecycle control, visibility, and access discipline, as described in the Ultimate Guide to NHIs and aligned with the identity governance principles in NIST Cybersecurity Framework 2.0.
The most common misapplication is treating NHI sprawl as a simple cleanup project, which occurs when teams delete obvious leftovers but never establish ownership, rotation, and decommissioning controls for new identities.
Examples and Use Cases
Implementing control over NHI sprawl rigorously often introduces operational friction, requiring organisations to balance faster delivery against stricter identity lifecycle governance.
- A development team creates a new API key for each release pipeline, but no one tracks which keys are still active after the application is retired.
- A cloud platform uses short-lived service accounts for automation, yet fallback credentials remain in a secrets vault long after the automation path changes.
- An M&A integration leaves duplicate OAuth clients in place across two directories, making it unclear which identity is authorized for production traffic.
- A CI/CD workflow embeds credentials in code comments and ticketing systems, creating hidden identities that never appear in the official register; this pattern is echoed in the Top 10 NHI Issues.
- A security team applies Zero Trust principles by reducing standing access for machine identities, but must reconcile that with automation uptime and release velocity, which is where NIST Cybersecurity Framework 2.0 guidance becomes useful.
These use cases show why NHI sprawl is often discovered during audits, incident response, or migration projects rather than during normal operations. The broader lifecycle context is covered in the Ultimate Guide to NHIs — Key Challenges and Risks, especially where ownership gaps and weak rotation practices intersect.
Why It Matters in NHI Security
NHI sprawl expands the attack surface because every unmanaged identity can become a persistence path, privilege escalation point, or lateral movement pivot. It also weakens governance: if no one knows who owns an identity, no one is accountable for rotation, revocation, or exception handling. That is why NHI sprawl is often a precursor to credential leakage, over-privilege, and dormant access that survives organizational change. In the 52 NHI Breaches Analysis, the pattern is consistent: machine identities become breach enablers when visibility and lifecycle controls are missing. NHIMG research also shows that 91% of former employee tokens remain active after offboarding, underscoring how fast unmanaged identities can outlive their business purpose, according to The 2025 State of NHIs and Secrets in Cybersecurity.
Organisations typically encounter the consequences only after a leaked token, failed audit, or incident response review exposes how many machine identities were never formally retired, at which point NHI sprawl becomes operationally unavoidable to address.
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-02 | Covers secret and identity lifecycle failures that drive uncontrolled NHI growth. |
| NIST CSF 2.0 | PR.AC-1 | Identity and access governance requires knowing which machine identities exist and why. |
| NIST Zero Trust (SP 800-207) | SP 800-207 | Zero Trust depends on minimizing standing access and verifying each workload identity. |
Inventory every machine identity, assign ownership, and retire unused credentials on a fixed schedule.
