Secret vault sprawl is creating governance gaps across NHI estates

At a glance

What this is: This article argues that secret silos and vault sprawl undermine visibility, governance, and compliance for machine identities and privileged credentials.

Why it matters: It matters because IAM, PAM, and NHI teams cannot govern what they cannot see, especially when secrets are duplicated across cloud, Kubernetes, and self-managed vaults.

By the numbers:

• 44% of NHI tokens are exposed in the wild, being sent or stored over platforms like Teams, Jira tickets, Confluence pages, and code commits.
• 91% of former employee tokens remain active after offboarding, leaving organisations vulnerable to potential security breaches.

👉 Read Akeyless's analysis of secret silos and vault sprawl

Context

Secret silo sprawl is a governance problem, not just a storage problem. When credentials, certificates, and keys are scattered across cloud vaults, Kubernetes secrets, and self-managed platforms, teams lose the ability to enforce consistent access control, rotation, and auditability across the non-human identity estate.

In identity terms, the issue is that each vault becomes its own policy boundary. That fragments ownership, weakens lifecycle management, and makes it harder to prove who can use which secrets, when they were issued, and whether they were ever retired. The result is a control gap that grows with every environment added to the stack.

The article frames centralisation and vaultless management as the answer, but the deeper point is governance coherence. Organisations do not just need a place to store secrets, they need a way to govern them as identities with lifecycle, access, and accountability requirements.

Key questions

Q: How should security teams govern secrets across multiple vaults?

A: Security teams should govern multi-vault environments above the storage layer. That means creating one inventory of all secrets, mapping ownership and consumers, and enforcing the same rotation and expiry rules across every store. Without that cross-vault layer, each vault becomes a separate island of privilege with its own blind spots.

Q: Why do secret silos increase machine identity risk?

A: Secret silos increase machine identity risk because the same credential can be copied, reused, or forgotten in multiple environments. That widens the blast radius of compromise and makes it harder to know which applications still depend on an exposed secret. A distributed secret estate also slows detection and revocation.

Q: What breaks when secret rotation is managed separately in each vault?

A: Rotation breaks down when each vault follows its own schedule, owner, and approval path. The result is inconsistent lifecycle control, stale credentials that survive longer than intended, and audit evidence that cannot be reconciled quickly. In practice, that makes the organisation slower to contain incidents and harder to defend under review.

Q: Which frameworks should teams use to evaluate secret sprawl risk?

A: Teams should use OWASP Non-Human Identity Top 10 for NHI governance, NIST Cybersecurity Framework 2.0 for control alignment, and NIST SP 800-53 Rev 5 Security and Privacy Controls for access control and authentication. Those frameworks help translate vault sprawl into specific control gaps and remediation priorities.

Technical breakdown

Why secret silos break governance at scale

A secret silo forms when teams store credentials in separate vaults tied to specific projects, clouds, or platforms. That may work early on, but it becomes brittle once rotation, revocation, and access review must happen across many systems. Each new vault adds a new policy surface, a new administrative model, and a new place where visibility can fail. The problem is not simply duplication. It is that control decisions stop being consistent, which makes audit evidence incomplete and incident response slower.

Practical implication: treat every new vault as a governance expansion, not just an infrastructure choice.

How machine identity risk grows when secrets are distributed

Machine identities rely on secrets such as API keys, certificates, and tokens to authenticate and act. When those secrets are copied into multiple vaults or embedded in platform-specific tooling, the same identity can be overused across applications and environments. That increases blast radius because compromise of one secret may expose many workloads. It also complicates ownership, because no single team can reliably prove where the secret lives, who uses it, or whether it still has a valid business purpose.

Practical implication: map each secret to a single accountable owner and a single lifecycle record.

What vaultless or centralised control changes technically

A centralised secrets model tries to collapse fragmented vault policy into one source of truth, while a connector model overlays governance on existing vaults. Technically, both approaches aim to restore observability, standardise access enforcement, and reduce the number of unmanaged secret stores. The key difference is whether the organisation is willing to migrate secrets or simply federate control. Either way, the control objective is the same: make secrets discoverable, auditable, and revocable across the full environment.

Practical implication: choose the operating model that restores inventory, rotation, and revocation before considering convenience.

Threat narrative

Attacker objective: The objective is to exploit trusted machine access to move laterally, expand compromise, and reach sensitive services or data.

1. Entry occurs when secrets are distributed across multiple vaults, cloud-native stores, and local platforms, creating numerous places where credentials can be exposed or reused.
2. Escalation follows when a compromised secret enables access to multiple workloads or environments, especially where the same machine identity is overused across applications.
3. Impact arrives as attackers pivot through trusted service access, increasing blast radius, weakening detection, and making containment slower and more expensive.

Breaches seen in the wild

• 230M AWS environment compromise — 230M AWS environments compromised via exposed .env files with cloud credentials.
• Google Firebase misconfiguration breach — Firebase misconfigurations exposed 19.8M secrets across developer instances.

Read our 52 NHI Breaches Analysis report for a comprehensive view of breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Secret silo sprawl is a visibility failure before it is a storage failure. Once credentials, certificates, and keys are split across vaults, teams stop having a complete inventory of who can access what. That breaks governance because access review, rotation, and incident response all depend on a trustworthy secret map. The practitioner conclusion is simple: if the inventory is fragmented, the control plane is fragmented too.

Machine identity governance collapses when the same secret is reused across multiple applications. The article describes exactly the kind of overextension that turns one credential into a cross-environment compromise path. That is not just poor hygiene, it is a blast-radius problem, because one exposed secret can represent many workloads. Practitioners should treat secret reuse as a structural risk, not an exception to clean up later.

Vault centralisation and vault federation solve different governance problems. A single source of truth improves control when the organisation can migrate, but connector-based management is the practical bridge when migration is not realistic. The important point is not the product path, it is the governance outcome: secrets must be discoverable, revocable, and attributable across the full estate. Identity teams should judge the model by control coherence, not by deployment preference.

Secret silos are where PAM and NHI programmes lose their shared operating model. PAM traditionally focuses on elevated access, while NHI governance focuses on machine identities and service credentials. In vault sprawl, those domains overlap without a common lifecycle, which is why secrets linger after teams change, projects end, or environments shift. The implication is that privilege governance must cover both human and non-human access paths together.

Vault sprawl creates compliance theatre when audit evidence cannot follow the secret. If access, logging, and ownership are split across systems, then control claims are easy to make but hard to prove. That is where the governance assumption fails: compliance requires traceability, not just storage. Practitioners should read distributed vaults as a maturity signal, not merely a tooling preference.

From our research:

• 91% of former employee tokens remain active after offboarding, leaving organisations vulnerable to potential security breaches, according to The 2025 State of NHIs and Secrets in Cybersecurity.
• 62% of all secrets are duplicated and stored in multiple locations, causing unnecessary redundancy and increasing the risk of accidental exposure.
• That pattern reinforces the need for lifecycle-led governance, as outlined in the NHI Lifecycle Management Guide, not vault-by-vault administration.

What this signals

Secret sprawl is a lifecycle failure as much as an architecture failure. When credentials are duplicated across platforms, the organisation loses the ability to prove which secret is authoritative, which is why the next governance step should be moving from store-centric thinking to identity-centric control. The OWASP Non-Human Identity Top 10 gives teams a useful control vocabulary for that shift.

Identity blast radius: the more places a secret lives, the more likely one compromise becomes many compromises. That is why distributed vault management should be treated as an exposure multiplier, not a resilience strategy, especially when service accounts and automation depend on the same underlying credentials.

For programmes that still need multiple vaults, the priority is not platform consolidation for its own sake, but operational coherence across rotation, offboarding, and emergency revocation. The practical test is whether a security team can answer, from one view, where a secret exists, who uses it, and how fast it can be withdrawn.

For practitioners

• Build a unified secret inventory Catalogue every vault, secret store, and embedded credential location across cloud, Kubernetes, and self-managed environments. Tie each item to an owner, a business application, and a retirement date so inventory supports governance rather than merely discovery.
• Reduce secret duplication across environments Identify where the same credentials, certificates, or tokens appear in multiple places and remove duplicates where feasible. Use the Guide to the Secret Sprawl Challenge to structure remediation around sprawl sources, not just individual leaks.
• Enforce lifecycle controls on machine identities Apply rotation, revocation, and offboarding rules to the secrets that power service accounts, workloads, and automation tools. The NHI Lifecycle Management Guide is the right reference point when you need governance that follows the identity, not the vault.
• Separate migration decisions from governance decisions Decide first whether the organisation needs a single source of truth or federated control over existing vaults. Then evaluate whether the current model can support centralized access review, audit logging, and emergency revocation across all secret stores.
• Map secret sprawl to established controls Align vault governance to OWASP Non-Human Identity Top 10 and NIST Cybersecurity Framework 2.0 so ownership, visibility, and revocation expectations are explicit. That helps security, IAM, and platform teams work from the same control language.

Key takeaways

• Secret silos turn a storage decision into an identity governance problem because visibility, rotation, and ownership fragment across vaults.
• Distributed credentials expand blast radius, especially when the same secret is reused across multiple applications or environments.
• The right response is lifecycle-led control, whether that means centralising secrets or governing multiple vaults through one policy layer.

Key terms

• Secret Silo: A secret silo is a separate storage location where credentials, certificates, or keys are managed independently from the rest of the estate. In practice, siloing fragments ownership, rotation, auditability, and incident response, creating hidden control boundaries that are difficult to govern consistently.
• Vault Sprawl: Vault sprawl is the uncontrolled growth of secret stores, vault instances, and duplicate credential repositories across an organisation. It creates fragmented access control, unclear ownership, and inconsistent rotation practices, which makes it difficult to prove where a secret lives or whether the authoritative copy is still in use.
• Machine Identity: The digital identity of a machine, device, or workload — such as a server, container, or VM — used to authenticate it within a network. Sometimes used interchangeably with NHI, though NHI is the broader category.
• Secrets Lifecycle: Secrets lifecycle is the management of credentials from issuance through rotation, revocation, and offboarding. It matters because a secret that is technically valid can still be operationally unsafe if its owner, purpose, or downstream access paths are no longer current.

What's in the full article

Akeyless's full article covers the operational detail this post intentionally leaves for the source:

• Step-by-step migration planning for moving secrets into a centralized management system.
• Practical guidance on using a universal secrets connector to manage AWS, Azure, Google Cloud, and Kubernetes vaults together.
• Role-based access control considerations for updating, deleting, and auditing distributed secrets from one platform.
• Implementation trade-offs between a fully vaultless model and a federated vault management approach.

👉 Akeyless's full article covers migration options and universal connector details for distributed vault governance.

Deepen your knowledge

NHI governance, agentic AI identity, and machine identity lifecycle are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building or maturing an identity security programme, it is worth exploring.