How should security teams manage third-party access in a TPRM programme?

Why This Matters for Security Teams

Third-party access is often where TPRM breaks down in practice: vendors are approved on paper, but the actual identities behind the connection drift over time. Shared accounts, long-lived API keys, OAuth grants, and service principals can persist well after the business need has changed. That creates a control gap between procurement, IAM, and operations. NHI governance is designed to close that gap by treating access as something that must be owned, reviewed, and revoked across the full lifecycle, not just at onboarding. NHI Mgmt Group research shows Ultimate Guide to NHIs documents that 92% of organisations expose NHIs to third parties, which makes vendor-connected identities a routine exposure rather than an edge case. That concern aligns with the visibility emphasis in NIST Cybersecurity Framework 2.0, especially where access governance and monitoring must work together. In practice, many security teams discover third-party access only after a vendor relationship has changed, rather than through intentional lifecycle management.

How It Works in Practice

Security teams should manage third-party access as a set of linked identities, secrets, and approvals. Start by inventorying every vendor-facing account, token, certificate, OAuth app, and integration, then assign a business owner and a technical owner for each one. That inventory should distinguish between human vendor users and machine-to-machine access, because the control requirements differ. For the machine side, the practical target is least privilege plus short-lived access: JIT issuance where possible, narrow scopes, and automated expiry or revocation when the task ends. Where organisations use vaulting or federation, the key question is whether the third party can authenticate without receiving a durable secret that outlives the contract.

• Bind each third-party identity to a named internal owner, approved purpose, and explicit revocation path.
• Separate read-only, administrative, and support access so vendors do not inherit broad operational rights.
• Review OAuth grants, API keys, and service accounts on trigger events such as scope changes, incident tickets, offboarding, or inactivity.
• Log every vendor action and connect it to the identity used, not just to the organisation name.

The OWASP Non-Human Identity Top 10 is useful here because it frames the most common failure modes: over-privilege, poor rotation, and weak visibility. For lifecycle context, Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs is the clearest reference point. These controls tend to break down when third parties connect through shared platforms, because ownership becomes blurred and revocation paths stop being operationally testable.

Common Variations and Edge Cases

Tighter vendor control often increases operational friction, so organisations have to balance faster support and integration delivery against stronger access governance. That tradeoff is real, especially when a managed service provider needs broad visibility across multiple environments or when a SaaS vendor relies on OAuth delegation rather than direct account access. Current guidance suggests treating those cases as exceptions that require compensating controls, not as reasons to skip review altogether. For example, broad support access can sometimes be acceptable if it is time-bound, logged, and tied to ticketed approvals, but there is no universal standard for this yet.

Another common edge case is tooling that creates access automatically, such as CI/CD integrations, chatops bots, and external automation platforms. In those environments, the control should focus on intent and expiry rather than static role assignment. The inventory must still show who approved the integration, what it can do, and how it is removed. NHI breach analyses from 52 NHI Breaches Analysis show how quickly dormant or overexposed secrets become an incident path, and the same lesson applies to vendors. Security teams should also compare their process against Top 10 NHI Issues and the governance expectations in NIST Cybersecurity Framework 2.0. The hardest cases are legacy vendors with no API for rotation or revocation, because manual offboarding becomes the only reliable control.

Related resources from NHI Mgmt Group

• How should security teams start a third party risk management programme from scratch?
• How can security teams know whether third-party risk management is working?
• How should organisations manage third-party access as part of IAM governance?
• How should security teams run access reviews for non-human identities?