Least privilege across humans and NHIs remains the control gap

At a glance

What this is: NHI Mgmt Group's analysis, drawing on Opti's blog post: Least privilege must now cover human and non-human identities alike, because broad permissions expand attack paths and magnify the impact of compromise.

Why it matters: IAM, PAM and IGA teams need to treat service accounts, tokens and AI agent permissions as first-class governance objects, not as exceptions to human access policy.

Context

Least privilege only works when access is scoped to the actual task, not to convenience or historical habit. In modern environments, that scope has to be enforced across people, workloads, service accounts and AI-enabled automation, because each of those identity types can carry permissions that outlive the moment they were needed.

The governance gap is not the principle itself. It is the gap between a clean access model and the way permissions accumulate in cloud, SaaS and automated workflows. Least privilege techniques matter here because excess access tends to survive through role drift, dormant entitlements and informal exception handling.

When non-human identities are treated as infrastructure details rather than governed identities, they become a quiet source of broad access and weak accountability. That is typical in mature-enough environments that have scaled quickly, and it is one reason least privilege programs often stall at the human-user layer.

Key questions

Q: Why do service accounts and other NHIs complicate GRC implementation?

A: NHIs complicate GRC because they often outnumber human accounts, change outside normal HR-driven lifecycle processes, and carry access that is easy to overlook in reviews. If inventory, ownership, and expiry are incomplete, the GRC programme will miss the most material access risks. That makes NHI governance a core compliance issue, not a niche security task.

Q: Why do static roles often fail to enforce least privilege in cloud environments?

A: Static roles often fail because cloud permissions change faster than job functions, so broad, long-lived assignments accumulate over time and create privilege creep. Least privilege is better enforced with role mining, attribute-based access control, just-in-time elevation, and frequent entitlement reviews so access matches the workload, environment, and current task rather than a fixed job title.

Q: How can organisations reduce privilege creep without slowing operations?

A: Organisations reduce privilege creep by tying access to a named role or attribute, then reviewing entitlements on a fixed schedule and stripping unused rights through JIT elevation or PAM. Real usage data from access logs and application activity shows which permissions are actually needed, so dormant broad access can be removed without blocking legitimate work.

Q: What is the best way to limit blast radius after credential compromise?

A: The best way to limit blast radius after credential compromise is to keep the credential in the narrowest possible scope, with short-lived tokens, segmented permissions, and resource-level limits. If one secret is exposed, the attacker then inherits only the minimum API actions, data paths, or workload access tied to that identity.

Technical breakdown

Minimum necessary access across identity types

Minimum necessary access means each identity gets only the permissions required for a specific function, nothing more. The mechanism is simple in concept but hard in practice because the access scope must be mapped to a real business task, not just a job title or a technical role. In NHI-heavy environments, the same logic applies to service accounts, API keys and automation identities that act continuously across systems. When permission scope is broader than the task, compromise becomes more useful to an attacker and governance becomes harder to prove. See the IAM and IGA Basics.

Practical implication: Model permissions around specific tasks and system boundaries, then remove anything that cannot be justified against actual use.

Why RBAC alone breaks in dynamic environments

Role-based access control is efficient when work patterns are stable, but it becomes blunt when permissions need to change quickly across cloud services, temporary projects and machine workflows. A role can be too broad, too sticky or too disconnected from real usage. Attribute-based access control adds context such as time, location or device, which makes it better suited to environments where access should vary with risk or task state. The core issue is not that RBAC fails completely, but that static role design struggles to keep pace with how modern identities actually operate. See the Authorisation Models Guide.

Practical implication: Use role models for structure, then add contextual policy where role-based access is too coarse for operational reality.

Continuous access review and privilege creep

Continuous access review is the control pattern that keeps least privilege from degrading over time. It works by comparing granted access with actual usage so dormant or excessive entitlements can be removed before they become normalised. That matters because privilege creep usually arrives gradually through transfers, projects, exceptions and automation sprawl. In non-human estates, the same drift happens through long-lived credentials, duplicated integrations and stale service permissions. The review problem is not visibility alone. It is the absence of a lifecycle loop that revisits whether access still has a reason to exist. See the NHI Lifecycle Management Guide.

Practical implication: Tie review decisions to usage telemetry and lifecycle state so stale access can be removed before it becomes accepted risk.

Threat narrative

Attacker objective: The attacker wants to turn one valid identity into broad access across systems, data and control functions.

1. Entry occurs when an attacker obtains a valid human or non-human credential, such as a compromised account, API key or service identity with more access than it should have.
2. Escalation follows when overprivileged permissions allow the attacker to move beyond the original task scope into adjacent systems, data stores or administrative functions.
3. Impact is wider because the compromised identity can read, modify or spread into resources that were never necessary for its legitimate work.

Breaches seen in the wild

• Azure Key Vault Contributor escalation 2024: Datadog found Azure Key Vault Contributor could add itself to access policies and read every secret, key and certificate in a vault.

Read and download The State of NHI & AI Agent Breach Report 2026, covering 200+ breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Least privilege fails first as a governance discipline, not as a technical control. The central problem is not that access controls are unavailable. It is that organisations often define access in broad role terms and then allow exceptions, reuse and drift to create durable overreach. That is why the issue appears in both human and non-human estates, and why access scope must be treated as a lifecycle question, not a one-time configuration.

Overprivileged non-human identities are a structural attack surface, not an edge case. Service accounts, API keys and machine identities are often granted broad access so automation keeps working, but that convenience converts into standing blast radius when credentials are exposed. NHI lifecycle management matters because access that is never revisited becomes a permanent assumption, not a temporary allowance.

Static role design cannot keep pace with modern access demand. Cloud services, SaaS sprawl and automation workflows change too quickly for role catalogs that were built around stable job structures. The result is either overbroad roles or a trail of exceptions that nobody can govern cleanly. Practitioners should treat access model design as a moving target, not a one-off architecture decision.

Least privilege is now a shared control plane across human, machine and agentic identities. The article’s strongest implication is that identity governance cannot stop at employees because the most persistent access paths increasingly sit in workloads and automation. The practical conclusion is that access policy, review and revocation must all operate across identity classes with the same rigor.

From our research library:

• 97% of NHIs carry excessive privileges, increasing unauthorised access and broadening the attack surface, according to the Ultimate Guide to NHIs.
• Systems with least-privileged AI access had a 17% incident rate vs 76% for over-privileged systems. Organisations failing to scope AI access properly are 4.5x more likely to experience a security incident, according to the 2026 Infrastructure Identity Survey.
• Read next: Least Privilege Techniques Guide

What this signals

Identity scope is now the real security boundary. As cloud services, automation and AI agents expand, the difference between a contained incident and an enterprise-wide one increasingly depends on how tightly each identity is scoped at issuance time. AI agent authorisation becomes especially important when an actor can act across systems but should only touch a narrow workflow.

Least privilege programmes will keep failing if they stay focused on user access reviews alone. The sharper governance question is whether every credentialed identity, human or otherwise, has a reviewable reason to exist in its current form. That shifts the control from periodic cleanup to continuous entitlement discipline.

For practitioners

• Define minimum task scope for every identity Map each user, service account and automation identity to a specific business function, then remove permissions that are not required to complete that function.
• Move high-risk access to just-in-time issuance Replace persistent elevated permissions with time-bound access for administration, production changes and sensitive operations so standing privilege does not accumulate.
• Review dormant and unused entitlements continuously Use usage telemetry to identify permissions that have not been exercised recently, then revoke access that no longer has a live operational need.
• Apply least privilege to AI agents and service accounts Scope machine and agent permissions to approved tools, actions and data sources, and require separate approval for anything outside the defined workflow. See the AI Agent Authorisation Guide.

Key takeaways

• Least privilege is only effective when it is applied across both human and non-human identities, because broad access turns ordinary credential compromise into a wider incident.
• The same control problem appears in service accounts, API keys, workloads and AI agents, where permissions often outlive the task they were created for.
• Continuous review, tighter scoping and time-bound elevated access are the governance levers that reduce attack surface and limit blast radius.

Related NHI Mgmt Group resources: Least Privilege Techniques Guide · NHI Lifecycle Management Guide · Privileged Access Management Guide · AI Agent Authorisation Guide

Key terms

• Principle of least privilege: The principle of least privilege means giving each identity only the access required to complete its current task. In practice, that means reducing default permissions, isolating administrative rights, and removing access as soon as the need ends so excess privilege does not become persistent risk.
• Non-Human Identity (NHI): A digital identity assigned to a non-human entity such as a software application, service account, API key, bot, machine, or AI agent that enables it to authenticate and interact with systems without direct human involvement. NHIs now outnumber human identities in most enterprises by 25 to 50 times.
• Role-Based Access Control: A model that grants permissions by assigning identities to predefined roles. It works well when jobs are stable and access patterns are predictable, but it becomes brittle when exceptions pile up. In practice, role design must stay small enough to audit and broad enough to avoid endless custom variants.
• Attribute-Based Access Control: Attribute-Based Access Control is a policy model that grants or denies access using attributes such as user role, device state, location, and application context. It replaces purely static role assignment with a decision process that can adapt to current conditions, provided the underlying attributes are trustworthy and well-governed.

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 IAM programme, it is worth exploring.