Because every server can introduce its own client registration, token store, and refresh logic, which multiplies credential-bearing assets without a common governance model. That is the same structural problem seen in NHI sprawl: more identities, more exceptions, and less visibility. The issue is not the protocol alone, but the way it fragments control.
Why This Matters for Security Teams
MCP creates sprawl for the same reason NHI programmes do: every new server or integration can bring its own credentials, tokens, scopes, and lifecycle rules, but without a consistent governance pattern. That means more credential-bearing assets, more exceptions, and less reliable inventory. The issue is not simply exposure, but fragmentation of control across toolchains and teams.
For security teams, this matters because unmanaged growth quickly turns into invisible privilege. The Ultimate Guide to NHIs notes that NHIs outnumber human identities by 25x to 50x in modern enterprises, and that scale is exactly why duplicated registrations and token stores become operational debt. In practice, the same pattern appears in OWASP Agentic AI Top 10 discussions: when each workload negotiates access differently, governance becomes an afterthought instead of a control plane.
Current guidance suggests treating MCP endpoints as identity-bearing infrastructure, not just application plumbing. In practice, many security teams discover the sprawl only after a token leak, a shadow integration, or a failed offboarding event has already created exposure.
How It Works in Practice
MCP becomes sprawl when each server manages its own client registration, secrets, refresh flow, and permission model. That creates a mini identity system per integration, which is operationally familiar to anyone managing service accounts, API keys, or machine tokens. The more servers and connectors you add, the more likely it is that authentication logic, secret storage, and revocation drift apart.
A better pattern is to centralise the identity primitive and make access decisions at runtime. For autonomous or semi-autonomous tool use, current best practice is evolving toward workload identity, short-lived credentials, and policy-as-code. That means the server or agent proves what it is, receives ephemeral access only for the task, and loses it automatically when the task ends. This is the same logic behind zero standing privilege and just-in-time credential issuance.
Practically, that can look like:
- Using workload identity as the source of truth instead of long-lived shared secrets.
- Issuing short TTL tokens per task rather than keeping permanent refresh tokens in each server.
- Evaluating policy at request time, not only at registration time.
- Logging every registration, scope change, and token minting event for inventory and review.
That guidance aligns with the NHI lifecycle emphasis in the Top 10 NHI Issues, especially around rotation, visibility, and offboarding. It also fits the emerging control logic in OWASP Top 10 for Agentic Applications 2026, where dynamic tool use makes static authorization brittle. These controls tend to break down when teams allow every MCP server to maintain its own long-lived secret store because revocation, attribution, and scope review no longer happen in one place.
Common Variations and Edge Cases
Tighter central control often increases integration friction, requiring organisations to balance developer velocity against identity consistency. That tradeoff is real, especially where teams need fast onboarding for new MCP servers or partner-facing connectors.
There is no universal standard for MCP governance yet, so organisations should avoid pretending the protocol itself is the control. Some environments will use a central broker for registration and token issuance, while others will rely on federated workload identity and policy enforcement at the edge. The right answer depends on whether the main risk is secret proliferation, excessive privilege, or weak revocation discipline.
Edge cases matter. A small internal deployment may tolerate some local autonomy, but multi-team and multi-tenant environments usually do not. The sprawl problem is amplified when MCP servers are deployed by application teams outside IAM review, or when credentials are embedded in CI/CD, code, or container images. The Ultimate Guide to NHIs — Key Challenges and Risks and the 52 NHI Breaches Analysis both reinforce the same operational lesson: once secrets and privileges proliferate, containment becomes much harder than prevention.
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, OWASP Agentic AI Top 10 and CSA MAESTRO address the attack and risk surface, while NIST AI RMF 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-03 | Covers NHI secret sprawl and weak lifecycle control from repeated MCP registrations. |
| OWASP Agentic AI Top 10 | A2 | Agentic systems need runtime authorization because tool use changes per task. |
| CSA MAESTRO | IAM | MAESTRO addresses identity governance for autonomous workloads and tool chains. |
| NIST AI RMF | AI RMF applies to runtime oversight, accountability, and misuse of autonomous integrations. | |
| NIST Zero Trust (SP 800-207) | AC-6 | Zero Trust supports least privilege and continuous verification for MCP-linked workloads. |
Inventory MCP-issued credentials and enforce rotation, revocation, and ownership for every server.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on August 20, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
