TL;DR: New federal guidance for operational technology makes Zero Trust the operational baseline, according to Xage Security, but only when it is adapted for high availability, legacy equipment, and safety constraints that can be broken by active scanning, dynamic isolation, or direct IT and OT identity coupling. The real governance shift is that OT trust must be enforced at access time and asset level, not assumed at the perimeter.
At a glance
What this is: This is an analysis of new federal Zero Trust guidance for operational technology, with the central finding that OT security must move from perimeter assumptions to identity-aware controls, segmentation, and resilience.
Why it matters: It matters because OT teams, IAM leads, and security architects have to govern privileged access, third-party connectivity, and legacy-system constraints without disrupting safety or availability.
Context
Operational technology security fails when controls assume enterprise-style freedom to scan, isolate, or authenticate without consequence. In industrial environments, availability and safety come first, so the control model has to fit the process, not the other way around.
The article frames a genuine governance problem: how to apply Zero Trust to OT without breaking legacy systems or creating unsafe latency. That makes identity, remote access, and segmentation part of operational resilience, not just cybersecurity design.
Key questions
Q: What breaks when Zero Trust is applied to OT without safety-aware design?
A: Zero Trust fails in OT when it assumes enterprise-style flexibility. Active scanning, aggressive isolation, or poorly timed authentication can disrupt control loops, break availability, or trigger unsafe conditions. The right model treats segmentation, identity, and monitoring as operational controls that must preserve process continuity while limiting access.
Q: Why does weak third-party software oversight increase risk in converged IT and OT environments?
A: Weak third-party oversight increases risk because modern operational environments depend on external software, device stacks, and remote connectivity that can become attack paths. If vendors ship vulnerable components or poor security design, those weaknesses move into the customer environment. Organizations need proactive vendor assessments, secure development expectations, and access controls that apply consistently across mainframe, OT, and hybrid cloud systems.
Q: How should security teams handle third-party remote access to industrial systems?
A: Treat third-party access as a governed exception, not a permanent support channel. Use hardened jump hosts, session recording, MFA, and just-in-time approval so remote work is observable and revocable. That reduces the chance that a supplier account becomes a standing path into critical operations.
Q: What is the difference between agent-based and agentless Zero Trust in OT?
A: Agent-based Zero Trust relies on software installed on endpoints to enforce or observe policy, while agentless Zero Trust applies controls outside the device, usually at gateways or access layers. In OT, agentless designs are often safer because many legacy systems cannot tolerate added software, latency, or warranty risk.
Technical breakdown
Why perimeter trust fails in OT networks
Traditional OT networks were often designed around implicit trust, physical separation, and fixed operational relationships. That model breaks down once IT and OT connectivity expands, because attackers can move through trusted pathways, vendors can access systems remotely, and legacy protocols expose too much if segmentation is weak. Zero Trust changes the control point from network location to verified access intent, but in OT that must be done without introducing latency or blocking control traffic. The challenge is not simply to authenticate users more often. It is to ensure every request is checked against asset sensitivity, protocol constraints, and safety impact before access is granted. See the Zero Trust Identity Guide. See the Zero Trust Identity Guide.
Practical implication: Map trust boundaries to OT assets and protocols, not just network zones.
How identity and privileged access need to work in converged IT and OT
The article’s core identity issue is the danger of directly linking enterprise identity systems into OT environments without enough separation. In converged operations, shared identity infrastructure can create an escalation path across domains if credentials, authentication flows, or privilege models are reused carelessly. That is why layered ICAM, MFA, RBAC, credential vaulting, and JIT access matter here. OT requires tightly scoped access that can be approved, monitored, and removed without leaving standing pathways open. The governance point is not just stronger login controls. It is preventing identity coupling from becoming a cross-domain control failure. See the Ultimate Guide to NHIs. Read the Ultimate Guide to NHIs: Standards.
Practical implication: Separate OT privilege paths from enterprise identity planes and remove standing access where possible.
Why agentless controls matter for legacy endpoints
Many OT devices cannot support modern security agents, and some deployments cannot tolerate the instability those agents might introduce. That makes agentless enforcement a practical architecture choice, not a convenience. When controls are applied at the gateway, policy layer, or remote access path, teams can protect older PLCs, RTUs, and edge systems without modifying the endpoint or risking warranty and compatibility issues. This is especially important in OT because operational continuity is part of the security requirement. The technical lesson is that Zero Trust in OT often depends on external enforcement rather than endpoint instrumentation. See the Guide to SPIFFE and SPIRE. Read Guide to SPIFFE and SPIRE.
Practical implication: Use enforcement points outside the legacy device when endpoint agents are unsafe or unsupported.
Threat narrative
Attacker objective: The attacker seeks to reach and manipulate operational systems while evading the controls that protect safety and availability.
- Entry occurs through remote access, supply chain relationships, or other pathways that reach OT environments without requiring direct physical presence.
- Privilege escalation becomes possible when identity systems are coupled too tightly and standing access is left open across IT and OT domains.
- Impact follows when attackers, insiders, or third parties can move laterally in systems where safety, availability, and production continuity are tightly coupled.
Breaches seen in the wild
- Klue OAuth Supply Chain Breach: OAuth tokens compromised in Klue integration breach affecting 700+ organisations via Salesforce data access chain.
- Palo Alto Networks Salesforce data theft 2025: Stolen Drift OAuth tokens exposed Palo Alto Networks CRM data, including support notes where some customers had shared credentials.
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
Zero Trust in OT is now an operational governance problem, not a theoretical architecture debate. The article reflects a broader shift in critical infrastructure security: the question is no longer whether to remove implicit trust, but how to do it without interrupting production or safety systems. That changes the role of identity, segmentation, and remote access from optional hardening to baseline control design. Practitioners should treat OT Zero Trust as a resilience programme with safety constraints.
Identity coupling is the most fragile part of converged IT and OT security. Once OT access depends on shared enterprise identity structures, attackers gain a route to cross domains, and operational teams lose the separation they need to contain failures. The article’s emphasis on layered ICAM, MFA, RBAC, and JIT access shows that privilege scope matters more than network adjacency in modern industrial environments. Teams should audit where identity reuse creates hidden trust bridges.
OT trust boundary drift: implicit access paths, shared directories, and unmanaged vendor routes create the governance gap Zero Trust is meant to close. The article highlights a recurring pattern in industrial security: controls fail when they are layered onto legacy operations without rethinking who can reach what, through which channel, and under what approval model. That is why remote access governance and segmentation have to be designed together. Practitioners should look for trust bridges that were never formally approved.
Agentless enforcement is not a compromise position in OT, it is often the only viable one. Legacy endpoints, process sensitivity, and warranty constraints mean endpoint agents can be the wrong control even when their intent is sound. The article shows that OT security architecture must include enforcement points outside the device itself. For teams modernising industrial environments, the practical conclusion is to control access paths and protocol mediation, not to assume endpoint tooling will fit every asset.
From our research library:
- 90% of IT leaders say properly managing NHIs is essential for a successful zero-trust implementation, according to the Ultimate Guide to NHIs.
- Read next: Zero Trust Identity Guide
What this signals
OT trust boundary drift: industrial environments are drifting away from implicit trust models that were never designed for interconnected IT, vendor access, and legacy protocols. Practitioners should expect Zero Trust programmes to shift from network design debates to governance over who can touch which asset, under what conditions, and through which mediation layer.
Zero Trust in OT will increasingly be judged by whether it preserves uptime while narrowing access. That means the practical test is not whether every control looks modern, but whether the access model can reduce exposure without introducing unsafe latency or breaking process continuity.
The article also reinforces that identity is now a core OT control surface, not an enterprise-only concern. When remote access, privileged approval, and third-party connectivity are all identity-mediated, teams need governance that aligns access scope with operational consequence.
For practitioners
- Define OT trust boundaries by asset and protocol Document which PLCs, RTUs, edge systems, and control applications need separate policy zones, then enforce access based on process criticality and protocol sensitivity rather than broad network membership.
- Separate OT identity from enterprise directory paths Review where Active Directory or other shared identity systems are used directly in OT, then break cross-domain coupling with layered ICAM, MFA, and tightly scoped roles.
- Restrict third-party remote access to controlled entry points Require hardened termination hosts, session recording, and JIT access for vendors and contractors so that remote support does not become a standing lateral-movement path.
- Use agentless enforcement on legacy assets Place policy enforcement at gateways, tunnels, or access brokers when endpoint agents would disrupt operations, void warranties, or fail compatibility testing.
- Test segmentation against operational failure conditions Validate that microsegmentation and identity-aware access rules do not interrupt control loops, alarm handling, or safety interlocks during normal and degraded operation.
Key takeaways
- The article argues that OT Zero Trust has to be adapted to safety, uptime, and legacy constraints rather than copied from enterprise networks.
- Identity coupling, standing privileged access, and unmanaged vendor routes are the governance weak points that matter most in converged IT and OT environments.
- Agentless enforcement, segmented access, and JIT remote access are the controls that make Zero Trust workable when OT endpoints cannot absorb conventional tooling.
Related NHI Mgmt Group resources: Zero Trust Identity Guide · Ultimate Guide to NHIs: Standards · SaaS-to-SaaS and OAuth App Governance Guide · Guide to SPIFFE and SPIRE
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK and OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST CSF 2.0 and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | PR.AA-05 — Access Permissions, Entitlements and Authorizations | The article focuses on identity-bound access control in converged OT environments. |
| PR.IR-01 — Network Architecture | Microsegmentation and trust boundaries are central to the guidance discussed. | |
| Recommendation — Apply PR.AA-05 to scope OT entitlements by asset criticality and remove broad shared access. Design network architecture so OT traffic is segmented around control paths and protocol sensitivity. | ||
| NIST SP 800-53 Rev 5 | AC-6 — Least Privilege | Least privilege is the core principle behind JIT access and constrained vendor support paths. |
| Recommendation — Use AC-6 to restrict OT support access to the minimum required scope and duration. | ||
| MITRE ATT&CK | TA0008;TA0040 — Lateral Movement; Impact | The article explicitly warns about lateral movement and operational harm in OT environments. |
| Recommendation — Map OT exposure to lateral movement and impact techniques, then prioritise controls that block cross-zone progression. | ||
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | The article’s remote-access and identity controls also apply to non-human service identities used in OT support. |
| Recommendation — Review machine and service accounts used in OT support for overprivileged access and tighten their scopes. | ||
Key terms
- Operational Technology Zero Trust: A security model that applies continuous verification and least privilege to industrial systems that control physical processes. It differs from enterprise Zero Trust because availability, deterministic communications, and safety constraints shape where enforcement can be introduced and how aggressively policy can change.
- Identity-aware Segmentation: Identity-aware segmentation is a containment approach that allows or blocks traffic based on trustworthy device identity and communication context. It is more resilient than location-based controls because lateral movement is constrained by who or what the device is, not just where it sits on the network.
- Just-in-Time Access Request: Just-in-Time Access Request is a pattern that grants access only when it is needed and only for the duration required. It reduces standing privilege by making access temporary, policy driven, and task scoped. This approach is especially useful for contractors, sensitive systems, and short-lived operational work.
- Agentless enforcement: A segmentation approach that applies control through existing infrastructure rather than installing software on every endpoint. It matters when legacy systems, IoT devices, and constrained workloads cannot host agents, because coverage must still reach those assets if the control is to be complete.
Deepen your knowledge
NHI Mgmt Group covers identity security, NHI governance, and agentic AI through independent research, practitioner guides, and the NHI Foundation Level course, the industry's only accredited NHI security programme. It is designed for practitioners building stronger identity controls across cloud, OT-adjacent, and hybrid environments.
Published by the NHIMG editorial team on October 22, 2026.
NHI Mgmt Group, the independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org