Secrets become easy to reuse across humans, scripts, and agents without a consistent audit trail. That increases the chance of exposure, weakens revocation, and makes it unclear which identity used the credential. A vault is only useful if it is the normal access path, not an optional store.
Why This Matters for Security Teams
Secrets that live outside a managed vault stop behaving like governed credentials and start behaving like shared text. They get copied into tickets, repos, chat threads, automation jobs, and local config files, which makes revocation slow and attribution weak. That is exactly the kind of sprawl NHI Management Group tracks in Guide to the Secret Sprawl Challenge and OWASP Non-Human Identity Top 10.
The operational issue is not just exposure. Once a secret exists in multiple unmanaged places, no one can confidently answer which copy is current, which workload used it, or whether offboarding removed all access paths. NHI Management Group research shows that 62% of all secrets are duplicated and stored in multiple locations, which turns a single credential event into a multi-system cleanup problem The 2025 State of NHIs and Secrets in Cybersecurity. In practice, many security teams discover the exposure only after the secret has already been reused across several systems.
How It Works in Practice
A managed vault changes the control point from “who can read this file” to “which identity is allowed to retrieve this secret, under what conditions, and for how long.” That matters because unmanaged storage breaks the chain of custody. If a secret sits in a code repository, a wiki, or a deployment variable, it becomes detached from identity, policy, and revocation. Current guidance from NIST Cybersecurity Framework 2.0 and OWASP is to treat secrets as governed assets, not convenience data.
In practical terms, a working model usually includes:
- central vaulting for all production secrets, with direct reads disabled outside approved paths
- short-lived access tokens or leases instead of long-lived static credentials
- identity-based policy for humans, services, and agents, so retrieval is tied to workload identity rather than a shared password
- automatic rotation and revocation when a secret is exposed, rotated, or no longer needed
- audit logging that records who or what retrieved the secret, when, and from where
For NHIs, the vault should be the default retrieval mechanism, not an optional backup store. That is especially important for CI/CD, ephemeral compute, and agentic automation, where credentials may be requested by software that has no stable user session. The lifecycle framing in Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs aligns with the same principle: the secret should be issued, used, and retired under a controlled identity workflow.
Teams also need to be clear about what counts as “outside the vault.” Local environment files, build logs, deployment manifests, chat exports, and issue trackers all qualify if they contain reusable credentials. A vault is only effective if every other copy is treated as an exception, not a parallel system of record. These controls tend to break down in hybrid environments with legacy scripts and ad hoc admin access because secrets bypass the vault to preserve speed.
Common Variations and Edge Cases
Tighter vault enforcement often increases operational friction, requiring organisations to balance security gains against deployment speed and legacy compatibility. That tradeoff is real, but current guidance suggests the answer is to remove exceptions over time rather than normalize them. There is no universal standard for every environment, especially where older applications cannot call a vault API directly.
Common edge cases include vendor tools that only accept static secrets, emergency break-glass accounts, and temporary migration periods where both vault-managed and legacy paths exist. In those situations, the key risk is drift: teams keep the fallback path after the migration window ends. NHI Management Group’s Top 10 NHI Issues and The 2024 State of Secrets Management Survey both reflect the same pattern, with organisations citing central management gaps and widespread concern about secrets sprawl.
One useful rule is to classify any secret stored outside the vault as time-bound technical debt, then set an owner, expiry date, and removal plan. If the exception has no expiry, it will usually become the new normal. The hardest failures appear when shared credentials are embedded in automation that no one actively maintains, because revocation then breaks production before the hidden copies are found.
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, 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 secret lifecycle management and unmanaged credential exposure. |
| NIST CSF 2.0 | PR.AA-1 | Identity proofing and access control are undermined when secrets are not vault-governed. |
| NIST CSF 2.0 | PR.DS-1 | Data-at-rest protection applies when secrets are stored in files, repos, or chat systems. |
| NIST AI RMF | Governance is needed when autonomous systems handle credentials outside human review. |
Centralize secrets, enforce rotation, and eliminate unmanaged copies outside approved vault paths.
