TL;DR: Manufacturers are managing access for an average of 20 vendors, yet only half maintain a comprehensive inventory, while 59% do not monitor third-party access at all, according to Imprivata. That combination turns vendor access into a supply chain control problem, not just a security hygiene issue.
At a glance
What this is: This article argues that unmonitored vendor access is becoming a manufacturing supply chain risk because inventories, monitoring, and privilege controls lag the scale of third-party connectivity.
Why it matters: IAM, PAM, and NHI teams in manufacturing need to treat vendor accounts, contractor access, and fourth-party exposure as governed identities, not informal operational exceptions.
By the numbers:
- Manufacturers manage access for an average of 20 vendors, yet only half maintain a comprehensive inventory.
- 59% don’t monitor third-party access at all.
Context
Manufacturing supply chains now depend on a dense web of third-party access across Industrial IoT, cloud platforms, contractors, and support vendors. When those identities are not inventoried or monitored, access becomes an operational dependency with no reliable governance boundary.
The core problem is not vendor count alone. It is the combination of privileged access, shared workstations, legacy OT environments, and incomplete oversight that lets vendor access outgrow the controls meant to contain it.
Key questions
Q: What breaks when vendor access is not inventoried in manufacturing environments?
A: When vendor access is not inventoried, least privilege, review, and revocation controls all lose their reference point. Security teams cannot tell which external identities are active, which systems they can reach, or which relationships have ended. In manufacturing, that leaves production-connected access exposed long after the operational need has disappeared.
Q: Why does vendor access increase supply chain risk in plant environments?
A: Because vendor credentials often reach sensitive production, support, or engineering systems that are connected to operational workflows. If those identities are overprivileged or poorly monitored, a compromise of one supplier account can move into manufacturing operations, disrupt production, or expose intellectual property across connected systems.
Q: What are the signs that third-party access controls are failing in practice?
A: Common warning signs include broad or stale tokens, undocumented permission changes, open endpoints, inconsistent documentation, and vendor activity that blends into routine system traffic. Another signal is when teams cannot clearly explain who owns an integration or what happens if access must be revoked quickly. Those are usually indicators that governance has drifted.
Q: How should manufacturers control third-party access without slowing operations?
A: Use temporary, task-scoped access with explicit expiry, strong approval workflows, and detailed logging. Give vendors only the systems and sessions they need for the current job, then revoke access automatically when the task ends. That reduces exposure while preserving the collaboration manufacturing depends on.
Technical breakdown
Why third-party access becomes a governance blind spot
Vendor access in manufacturing often spans human contractor accounts, privileged support sessions, and system-to-system connections that sit outside the primary employee IAM programme. Once that access is granted, teams frequently lose visibility into which vendor still needs it, which systems it can reach, and whether it is still justified. In operational environments, those gaps are amplified by shared endpoints, older OT systems, and production pressure that discourages disruptive reviews. The result is not just excessive access, but an identity estate that no longer has a reliable owner or lifecycle.
Practical implication: build a complete vendor inventory and tie each account to a named business owner and offboarding trigger.
How privileged access turns vendor identity into supply chain risk
Privileged vendor access is especially risky because it can cross from routine support into production-impacting systems, secrets, and administrative functions. When access tools are not trusted or monitored, they create a false sense of control while leaving the actual entitlement risk unchanged. In a manufacturing context, that matters because a single contractor or supplier compromise can cascade through connected plants, supply platforms, and downstream operations. This is why third-party access is not just an IT issue but a supply chain resilience issue.
Practical implication: apply privileged access controls and session oversight to every vendor path that can reach production or sensitive engineering assets.
Why fourth-party exposure changes the access model
Fourth-party exposure means a vendor’s own suppliers or service providers can indirectly reach your environment through delegated connectivity, integrations, or support chains. That expands the trust boundary beyond the contract you signed and into relationships you may not directly govern. In practical terms, the organisation is no longer only managing who it onboards, but also the hidden dependencies behind those vendors. This creates a larger attack surface for credential theft, privilege abuse, and supply chain compromise.
Practical implication: extend vendor risk reviews to downstream dependencies and require evidence of subprocessor or subcontractor access governance.
Threat narrative
Attacker objective: The attacker aims to use trusted vendor access as a durable path into production systems, enabling disruption, theft, or broader supply chain compromise.
- Entry begins through vendor or contractor access that is granted for support, integration, or operational continuity and then left insufficiently monitored.
- Credential abuse or excessive privilege allows an attacker to reuse that access across manufacturing environments, shared workstations, or connected supply systems.
- Escalation occurs when vendor access reaches privileged functions, production systems, or data pathways that were never intended to remain continuously open.
- Impact follows as access theft, ransomware spread, or production disruption moves from one supplier connection into broader manufacturing operations.
Breaches seen in the wild
- BeyondTrust breach 2024: A stolen BeyondTrust Remote Support API key let a China state-sponsored actor reset accounts and reach US Treasury workstations in 2024.
- Uber breach 2022: A contractor's stolen password and MFA fatigue gave a Lapsus$-linked attacker Uber's internal tools; Uber rotated keys to many services.
Read and download The State of NHI & AI Agent Breach Report 2026, covering 150+ breaches impacting Non-Human Identities including AI Agents.
NHI Mgmt Group analysis
Vendor access has become a supply chain identity problem, not a narrow security hygiene issue. Imprivata's data shows the problem is not just the number of vendors, but the lack of inventory, monitoring, and trust in the tools supposed to govern that access. In manufacturing, where operational continuity depends on third parties, ungoverned access becomes a structural exposure across production and support ecosystems.
Fourth-party exposure is the named concept manufacturers are still underestimating. A vendor's vendor can inherit reach into systems through integrations, support chains, or delegated connectivity, which means the actual trust boundary extends beyond the contract owner. That breaks the assumption that third-party governance ends at onboarding, and it forces programme owners to treat vendor dependencies as part of the identity estate.
Least privilege only works when it is applied to vendor identities as continuously governed entitlements. The article's 35% excessive-vendor-privilege figure shows that many incidents are not caused by access itself but by access that stays broader and longer than operational need. Manufacturers need to recognise that vendor access without lifecycle control is just standing risk with a supplier label.
Privileged access controls fail when they are trusted as proof instead of measured as behaviour. If 55% of organisations using privileged access tools do not trust them to reduce risk, the issue is not deployment but control validation. In manufacturing, the test is whether access is inventory-backed, monitored, and provably constrained across the full vendor lifecycle.
Manufacturing resilience now depends on identity governance across contractors, suppliers, and support chains. The control plane has moved from static access review to continuous vendor governance because production environments cannot absorb the latency of manual oversight. Practitioners should treat vendor access as part of operational resilience planning, not a side register owned by procurement or IT alone.
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.
- 92% of organisations expose NHIs to third parties, raising concerns about supply chain security, according to the Ultimate Guide to NHIs.
- Read next: Cloud PAM and CIEM Guide
What this signals
Vendor access governance now needs to be continuous, not periodic. Manufacturing environments cannot rely on quarterly review cycles when access is granted to contractors, support providers, and upstream vendors that can move between production and cloud systems. The control question is whether every third-party identity has a current owner, a current scope, and a current reason to exist.
Identity blast radius is the right lens for fourth-party exposure. The practical risk is not only who is directly onboarded, but how far a compromised vendor account can travel through connected plants, shared workstations, and delegated integrations. A smaller blast radius depends on tight scope, session control, and offboarding discipline across the full vendor chain.
For practitioners
- Establish a complete vendor identity inventory Catalogue every third-party account, support identity, and privileged pathway tied to manufacturing operations, then assign business ownership and offboarding responsibility.
- Enforce least privilege on contractor access Limit each vendor to the specific plant, application, or support function it needs, and remove broad standing access from shared or legacy environments.
- Monitor third-party sessions continuously Track who accessed what, when, and why for every vendor session, especially where privileged access tools are used in OT-adjacent environments.
- Extend governance to fourth-party dependencies Require visibility into vendor subcontractors, downstream service providers, and delegated support relationships that can inherit access into your environment.
- Replace manual review with automated controls Use workflow automation and conditional approval paths to reduce the 134 hours a week teams spend investigating third-party and privileged access risk.
Key takeaways
- Unmonitored vendor access in manufacturing is a governance failure because third-party identities can outlive the business need that created them.
- The article reports an average of 20 vendors per organisation and 59% with no third-party monitoring, showing how quickly visibility gaps can become systemic.
- Manufacturers should treat vendor identity inventory, least privilege, and continuous session oversight as core supply chain resilience controls.
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 MITRE ATT&CK address the attack and risk surface, while CIS Controls v8 and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 — Vulnerable Third-Party NHI | Third-party vendor access and fourth-party exposure are central to the article. |
| NHI-05 — Overprivileged NHI | The article cites excessive vendor privilege as a breach driver in manufacturing. | |
| NHI-07 — Long-Lived Secrets | Vendor access control depends on time-bounded credentials rather than persistent access. | |
| Recommendation — Inventory third-party identities and validate offboarding before access persists beyond need. Reduce vendor entitlements to the minimum required scope and remove standing privilege. Replace durable vendor credentials with short-lived access and enforce expiration. | ||
| CIS Controls v8 | CIS-5 — Account Management | Third-party account inventory and lifecycle control are the article's core governance gaps. |
| Recommendation — Apply account management controls to track, review, and revoke vendor access on schedule. | ||
| NIST CSF 2.0 | PR.AA-05 — Access Permissions, Entitlements and Authorizations | The article is about who can access what across vendor identities and privileged pathways. |
| Recommendation — Limit third-party permissions and validate entitlements against current business need. | ||
| MITRE ATT&CK | TA0006;TA0008 — Credential Access; Lateral Movement | The article describes access theft and movement through connected supplier environments. |
| Recommendation — Map vendor-access compromise to credential access and lateral movement detections. | ||
Key terms
- Fourth-Party Exposure: Fourth-party exposure is the risk that comes from a vendor's vendor, subcontractor, or downstream service provider having access into your environment. It extends governance beyond direct contracts and forces teams to understand delegated connectivity, inherited privilege, and where accountability starts to blur.
- Vendor identity inventory: A current record of the external identities, accounts, tokens, certificates, and integrations a supplier can use in an environment. It is essential for incident response because teams cannot revoke or validate access they have not explicitly mapped and assigned to an owner.
- Privileged Vendor Access: Privileged vendor access is external access with elevated reach, such as admin roles, broad API scope, or delegated control over sensitive systems. It is especially risky because it often persists longer than teams expect and can bypass normal internal checkpoints if it is not explicitly governed.
- Identity Blast Radius: The amount of damage a compromised identity can cause across systems, data, and infrastructure. In NHI environments, it is shaped by permissions, network reach, and administrative capability rather than by the credential alone. Reducing blast radius is a containment strategy that limits lateral movement and data exposure.
Deepen your knowledge
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Published by the NHIMG editorial team on June 25, 2026.
Updated on October 8, 2026.
NHI Mgmt Group, the independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org