Because the risk is no longer limited to what the vendor intended to test. If the environment can access customer-relevant systems, then a compromised evaluation can use that access to move laterally, copy secrets, or trigger downstream actions. Vendor questionnaires do not contain that risk unless they are tied to concrete identity reach and revocation paths.
Why This Matters for Security Teams
AI agent environments change vendor risk because the security boundary is no longer the vendor’s code alone. Once an evaluation, integration, or hosted agent can reach customer systems, the blast radius expands to whatever that identity can touch. That includes secrets, APIs, data stores, and downstream automation. Current guidance from the OWASP Agentic AI Top 10 and NIST AI Risk Management Framework is clear that autonomous systems require runtime controls, not just pre-contract assurances.
NHIMG research shows how often non-human identity exposure becomes real incident impact: in the 2024 ESG Report: Managing Non-Human Identities, Oasis Security & ESG found that 72% of organisations have experienced or suspect a breach of non-human identities. That matters in vendor programmes because an agent platform frequently carries more privilege than the questionnaire suggests, especially when access is delegated through tokens, service accounts, or tool connectors.
The practical mistake is treating an AI vendor like a static software supplier. Agentic environments behave more like active workload operators, and their access patterns can shift with prompts, tool chains, and workflow branching. In practice, many security teams encounter blast radius only after a vendor connection has already been granted broad identity reach, rather than through intentional scoping and revocation design.
How It Works in Practice
Blast radius grows when the vendor’s environment includes an identity that can authenticate into customer systems with standing access. An agent may not need human-style permissions to cause damage. If it can read a mailbox, query a database, invoke an API, or trigger a deployment step, it can often chain those actions into wider compromise. That is why static IAM and questionnaire-only reviews are weak controls for agent environments.
Current practice is moving toward runtime, context-aware authorisation. Instead of asking, “What role should this vendor have?”, teams ask, “What is the agent trying to do right now, and should this task be allowed?” That is the logic behind policy-as-code and just-in-time credential issuance. Short-lived tokens, per-task secrets, and workload identity reduce the window for misuse. For agent workloads, identity should prove what the workload is, not merely what a human administrator once configured.
Useful implementation patterns include:
- Use workload identity and short-lived tokens instead of shared long-lived secrets.
- Gate vendor access with least privilege and per-action approval where feasible.
- Log every tool call, token mint, and privilege escalation path for revocation review.
- Revoke access automatically when the task, session, or evaluation completes.
NHIMG’s OWASP NHI Top 10 and the CoPhish OAuth Token Theft via Copilot Studio analysis both reinforce the same point: if an agent can be tricked into authorising the wrong action, vendor trust boundaries collapse fast. These controls tend to break down when vendors insist on persistent integration tokens or when customer environments lack fine-grained revocation for downstream tool access.
Common Variations and Edge Cases
Tighter access scoping often increases operational overhead, requiring organisations to balance faster vendor onboarding against narrower, more auditable identity reach. That tradeoff becomes more visible in multi-agent workflows, where one agent may call another, or where an evaluation harness is reused across customers. Best practice is evolving, but there is no universal standard for whether shared sandboxes, per-tenant agents, or isolated evaluation accounts are sufficient.
The main edge case is a “safe” demo or test environment that still has live credentials, copied production data, or network paths back to customer resources. In that setup, blast radius is defined by connectivity, not intent. Another common exception is when vendors rotate tokens but leave refresh credentials, service principals, or API gateway permissions untouched. In those cases, credential TTL alone does not contain the risk.
For that reason, vendor risk programmes should assess three questions together: what the agent can reach, how quickly that access expires, and how it is revoked when behaviour changes. The most relevant external guidance comes from the CSA MAESTRO agentic AI threat modeling framework and the MITRE ATLAS adversarial AI threat matrix, which both stress attack-path thinking over checkbox governance. In practice, blast radius is largest when a vendor’s agent can pivot from one allowed tool into many unseen downstream systems.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Agentic AI Top 10, OWASP Non-Human Identity Top 10 and CSA MAESTRO address the attack and risk surface, while NIST AI RMF and NIST Zero Trust (SP 800-207) set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Agentic AI Top 10 | A-04 | Addresses agent tool misuse that expands vendor blast radius. |
| OWASP Non-Human Identity Top 10 | NHI-03 | Covers overprivileged non-human identities used by vendors. |
| CSA MAESTRO | TBD | Focuses on threat modeling agent chains and downstream impact. |
| NIST AI RMF | Supports governing autonomous AI risk, including delegated access. | |
| NIST Zero Trust (SP 800-207) | PR.AC-1 | Zero trust limits lateral movement from compromised vendor environments. |
Replace standing vendor credentials with short-lived, least-privilege NHI access.
