Security teams should treat SSO as one control in a broader IAM strategy, not a complete answer. Gaps appear when legacy, native, or web applications do not support SAML, and when organisations still manage encryption keys, certificates, and API keys outside the sign-in flow. Effective governance needs inventory, rotation, access review, and secure storage for every credential type.
Why This Matters for Security Teams
When SSO does not reach every application or secret type, the real risk is not just inconvenience. It is the creation of parallel credential paths that bypass governance, logging, and lifecycle controls. Legacy apps, native tools, partner portals, API keys, certificates, and encryption material often sit outside the sign-in flow, which means they do not inherit the protections security teams assume are already in place. That gap is a classic source of secret sprawl, and it is still common across mature environments.
Current guidance suggests treating SSO as one layer in a broader identity and secret management program, not as the control that closes the loop. NHIMG research on the Secret Sprawl Challenge shows how unmanaged credentials accumulate across environments, while the OWASP Non-Human Identity Top 10 frames exposed or poorly governed secrets as a persistent attack path. The operational issue is simple: if a system cannot federate, it still needs the same inventory, ownership, rotation, and review discipline as SSO-enabled apps. In practice, many security teams encounter credential misuse only after secrets have already been copied into scripts, pipelines, or ticket comments rather than through intentional control design.
How It Works in Practice
Effective handling starts with a complete inventory of credential types and where they are used. Security teams should separate human login access from workload access and then map every non-SSO dependency: local application accounts, service accounts, API keys, SSH keys, TLS certificates, database passwords, cloud access keys, and encryption keys. The NIST Cybersecurity Framework 2.0 supports this as a governance exercise, while NIST SP 800-63 Digital Identity Guidelines reinforces that identity assurance is only one part of access control.
From there, the practical model is to manage secrets as lifecycle objects, not static artifacts. That means assigning an owner, setting a purpose, defining a maximum TTL where possible, storing them in a dedicated secrets manager or HSM-backed system, and rotating them on schedule or on use. For credentials that cannot be federated, prefer short-lived tokens, certificate automation, and just-in-time issuance over hardcoded values. NHIMG guidance on static vs dynamic secrets is especially relevant here because the security improvement comes from reducing credential lifetime, not just hiding the value.
- Inventory all non-SSO applications and all secret types in one register.
- Classify which systems can federate, which need brokered access, and which require local credentials.
- Move secrets into a central vault or managed secret store with audit logs.
- Rotate credentials automatically and revoke them when owners change or applications are retired.
- Review access based on usage, not just on role membership.
The most important control is not the storage tool itself but the operating model around it: ownership, rotation, exception handling, and monitoring must be consistent across every secret class. These controls tend to break down in mixed legacy and SaaS environments because local admin accounts, embedded API keys, and certificate lifecycles are often maintained by different teams with different change processes.
Common Variations and Edge Cases
Tighter secret governance often increases operational overhead, requiring organisations to balance faster delivery against stronger lifecycle control. That tradeoff is most visible when systems cannot support SSO, MFA, or automated rotation. In those cases, current guidance suggests compensating with shorter-lived credentials, stronger segmentation, and tighter monitoring rather than accepting long-lived static secrets as normal.
There is no universal standard for every edge case yet. Some applications only support local accounts, some vendor appliances require shared credentials, and some legacy batch jobs still depend on files or environment variables. For those systems, the least-bad approach is to reduce exposure through vault injection, scoped service accounts, and certificate automation where available. The NHIMG Lifecycle Processes for Managing NHIs material is useful for defining what “managed” should mean across the full identity lifecycle, while the Top 10 NHI Issues highlights how quickly unmanaged credentials become an incident driver.
The practical exception is any environment that still depends on hardcoded secrets in code, CI/CD variables, or shared admin accounts. Those patterns are difficult to secure because they blur ownership and make rotation brittle. When that is the reality, the right response is not to trust SSO as coverage, but to treat the uncovered surface as a separate control domain with explicit remediation deadlines and compensating monitoring.
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 CSF 2.0, NIST SP 800-63 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 | Addresses secret sprawl and unmanaged non-human credentials outside SSO. |
| NIST CSF 2.0 | PR.AC-1 | Covers identity and access governance across systems that SSO does not reach. |
| NIST SP 800-63 | Supports identity assurance, federation, and stronger lifecycle controls for access. | |
| NIST AI RMF | Provides governance language for managing identity risk and operational accountability. | |
| CSA MAESTRO | Useful for workload identity and runtime control of secrets in automated environments. |
Use federation where possible and fall back to controlled, auditable credential handling where not.
Related resources from NHI Mgmt Group
- How should security teams handle credential migration when passwords are spread across spreadsheets, browser exports, and legacy managers?
- How should security teams handle risks from AI browser extensions?
- How should security teams handle password management when SSO is already in place?
- What do security teams get wrong about using APIs to manage user roles and application licences?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on August 28, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
