They are harder to govern centrally, so access often ends up broader than intended and visibility is weaker. That creates blind spots for malicious traffic, overbroad entitlements, and missed application behavior. Security teams should treat these apps as higher-risk until policy, logging, and local enforcement are explicit enough to show who can access what, when, and why.
Why This Matters for Security Teams
Unmanageable applications are risky in zero trust because Zero Trust depends on accurate identity, policy, telemetry, and enforcement at the application boundary. If an app cannot be centrally governed, security teams lose confidence in who can reach it, what it is allowed to do, and whether its behavior matches policy. That weakens the core assumptions behind NIST SP 800-207 Zero Trust Architecture.
The practical issue is not only access control. It is also drift: unmanaged apps accumulate stale secrets, local exceptions, and hidden dependencies that are never fully reviewed. NHIMG notes that only 5.7% of organisations have full visibility into their service accounts, and 90% of IT leaders say properly managing NHIs is essential for a successful zero-trust implementation in the Ultimate Guide to NHIs — Why NHI Security Matters Now. In practice, many security teams discover the weakest app only after lateral movement or an incident has already created the evidence trail.
How It Works in Practice
In a mature Zero Trust design, an application is not treated as “trusted” just because it sits on a private network. It must present a verifiable identity, operate under explicit policy, and emit logs that prove what it did. For manageable apps, that often means workload identity, short-lived credentials, and policy enforcement tied to request context rather than subnet location. The Guide to SPIFFE and SPIRE is useful here because it frames workload identity as a cryptographic control plane for services, not a network shortcut.
Security teams usually apply three practical checks:
- Can the application authenticate as a distinct workload, not as a shared service account?
- Are secrets, certificates, and tokens short-lived, rotated, and revoked when the app changes?
- Can policy be evaluated at request time using identity, device posture, data sensitivity, and destination?
This matters because unmanaged applications often bypass one or more of those checks. They may run with embedded credentials, undocumented admin paths, or local firewall exceptions that never appear in the central policy model. The result is broader-than-intended access and weaker detection, which conflicts with the governance focus in the Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs and with the visibility emphasis in NIST Cybersecurity Framework 2.0.
These controls tend to break down when legacy applications cannot support modern identity tokens, dynamic policy, or central logging because the only remaining option is broad network allowance.
Common Variations and Edge Cases
Tighter control of unmanageable applications often increases migration cost, so organisations must balance immediate risk reduction against operational disruption. That tradeoff is real, especially where legacy systems, OT-adjacent services, or vendor-managed software cannot be reworked quickly.
Current guidance suggests classifying these apps by containment difficulty rather than pretending they fit a standard Zero Trust pattern. Some can be wrapped with gateways, reverse proxies, or segmented access brokers. Others need compensating controls such as stronger monitoring, explicit allowlists, stricter secret handling, and faster offboarding. For applications that cannot present workload identity or support request-level policy, best practice is evolving toward treating them as exceptions with time limits, not permanent architecture.
NHIMG research shows how often this risk becomes systemic: the Top 10 NHI Issues highlights visibility, rotation, and excessive privilege as recurring failure points, while the Ultimate Guide to NHIs — Key Challenges and Risks explains why these weaknesses persist across application lifecycles. The operational takeaway is simple: if an app cannot be made observable and policy-enforced, it should be assumed higher-risk until its controls are proven.
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 Zero Trust (SP 800-207), NIST CSF 2.0 and NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST Zero Trust (SP 800-207) | 3.1 | Defines zero trust policy enforcement at request time for every application access. |
| NIST CSF 2.0 | PR.AC-4 | Access permissions must be managed and least privilege maintained for applications. |
| OWASP Non-Human Identity Top 10 | NHI-03 | Unmanaged apps often rely on weakly governed non-human credentials and secrets. |
| CSA MAESTRO | 2.1 | Agentic and workload governance needs explicit identity, policy, and observability. |
| NIST AI RMF | Risk management requires continuous monitoring of autonomous or opaque system behavior. |
Require per-request policy checks and remove implicit trust from unmanaged applications.
Related resources from NHI Mgmt Group
- Why do unmanageable applications create more security risk in remote and hybrid work environments?
- Why do third party applications and external access paths often create hidden authentication risk in regulated environments?
- Why do non-human identities create audit risk in modern environments?
- Why do valid credentials still create so much risk in zero trust environments?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on August 27, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
