How should security teams govern vendor access in a zero trust programme?

They should treat vendor access as part of the core identity model, not as a separate remote support exception. That means applying the same authentication, approval, least privilege, and session oversight controls used for internal privileged users, then reviewing whether external access is still justified on a task-by-task basis.

Why This Matters for Security Teams

Vendor access is often the shortest path from a legitimate business need to a high-impact breach. In a zero trust programme, that makes third-party access part of the core identity perimeter, not a remote support exception. Security teams need to govern vendors with the same discipline used for privileged internal users: strong authentication, explicit approval, least privilege, session oversight, and rapid revocation when the task ends.

The risk is structural. Vendors frequently need elevated access, operate across multiple systems, and may use shared support workflows that are difficult to audit. That creates the same kind of visibility and control gaps that show up in non-human identity programmes. NHIMG research notes that The State of Non-Human Identity Security found 85% of organisations lack full visibility into third-party vendors connected via OAuth apps, which is a warning sign for any zero trust design. NIST’s Cybersecurity Framework 2.0 and Zero Trust Architecture both reinforce continuous verification rather than trust by network location.

In practice, many security teams discover vendor overreach only after a support account, token, or remote session has already been reused beyond its intended scope.

How It Works in Practice

Good vendor governance starts by classifying every external access path as a privileged identity use case. That means each vendor must have a named owner, a business justification, a defined scope, and a time bound approval. The access path should be tied to a corporate identity lifecycle, not an informal helpdesk exception. For recurring work, many organisations now prefer task-based approvals and short-lived access over standing entitlements, because static access tends to outlive the original need.

Operationally, zero trust controls should cover the full session, not just the login. That includes strong MFA, device and location checks where appropriate, per-session logging, command or action recording for administrative tasks, and immediate revocation when the ticket closes. For lower-friction implementations, current guidance suggests combining PAM with just-in-time elevation, rather than granting broad VPN or shared bastion access. NHIMG’s Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs is useful here because vendor tokens and support credentials follow the same lifecycle problem as other privileged identities: issuance, use, rotation, and offboarding.

• Use named vendor identities, never shared accounts for production support.
• Approve access per task, system, and time window, not by blanket contract status.
• Record sessions and administrative actions so post-incident review is possible.
• Revoke tokens, API keys, and remote access paths automatically when work is complete.

For identity primitives, teams should align vendor access with workload and human identity standards where relevant. The OWASP Non-Human Identity Top 10 is especially useful when vendors authenticate through service accounts, OAuth apps, or automation tokens, because the control failure is often the same: persistent credentials with too much reach. These controls tend to break down when legacy remote support tools require shared jump hosts and long-lived exceptions because session-level oversight becomes inconsistent across systems.

Common Variations and Edge Cases

Tighter vendor controls often increase operational overhead, requiring organisations to balance faster support restoration against reduced privilege and stronger auditability. That tradeoff becomes sharper in manufacturing, OT, or 24/7 operations, where outages can create pressure to keep vendor paths permanently open. Best practice is evolving, but there is no universal standard for whether every emergency vendor path must be fully brokered in real time or can be pre-approved under narrowly defined break-glass conditions.

One common edge case is service providers that authenticate through OAuth apps, API integrations, or delegated admin models instead of interactive logins. Those access paths should still be treated as vendor identity and monitored accordingly. NHIMG’s State of Non-Human Identity Security and Top 10 NHI Issues both highlight why external integrations are a frequent blind spot: they are easy to approve once and hard to retire later. Where vendors support critical systems, current guidance suggests adding separate approval trails for production access, tighter logging retention, and explicit offboarding steps tied to contract end dates.

The practical rule is simple: if the vendor can change state, read sensitive data, or trigger automation, the access should be governed like any other privileged identity, not inherited from procurement status or network placement.

Related resources from NHI Mgmt Group

• How should security teams govern vendor access in a zero trust environment?
• How should security teams govern non-human identities that have persistent access?
• How should security teams govern API keys used for generative AI access?
• How should security teams govern privileged access after authentication?