Agentic sandboxing and downhill delegation for AI agent identity

At a glance

What this is: This is an analysis of how AI agent delegation chains, token relay, and scope creep create identity risk, with a focus on downhill authorization, DPoP, and sandbox testing.

Why it matters: It matters because IAM, PAM, and NHI programmes must govern autonomous-seeming agents as identity actors whose privileges can expand through delegation unless controls are designed for chained execution.

👉 Read Strata Identity's analysis of AI agent delegation chains and rogue access

Context

AI agent identity risk starts when delegation chains stretch authorization beyond the intent of the original request. In practice, each handoff from human to agent to service can widen effective access unless the programme enforces scope reduction and token binding.

For IAM teams, the issue is not whether an agent can call tools, but whether the identity model can stop privilege from accumulating across hops. That makes agent governance a lifecycle and authorization problem, not just an application integration problem.

Key questions

Q: How should security teams prevent AI agents from escalating privileges through delegation chains?

A: Security teams should make delegation one-way and scope-reducing at every hop. If an agent passes work to another agent or service, the next identity must inherit equal or lower privilege, never more. That rule should be enforced in token exchange policy, service authorisation, and runtime access checks so that privilege cannot accumulate across chained actions.

Q: Why do AI agents create more identity risk than ordinary automation?

A: AI agents create more identity risk because they can choose actions, call tools, and continue execution in ways that are not fully predetermined by a fixed script. That makes delegation harder to reason about, especially when tokens can move across services. The main risk is not intent, but unexpected access expansion through opportunistic behaviour.

Q: What breaks when bearer tokens are forwarded between AI agents?

A: Bearer tokens break down because possession alone becomes enough to reuse access. If one agent can forward a token to another component, the original authority can travel far beyond the intended session. That is why token binding matters: it turns a reusable credential into one that is only valid for the intended holder.

Q: How can organisations test AI agent access before production use?

A: Organisations should run agentic sandbox scenarios that model escalation attempts, delegation cascades, scope creep, and token relay attacks. The goal is to expose where permissions expand, where tokens can be reused, and where services inherit too much authority. Testing should focus on actual identity behaviour, not just whether the workflow completes successfully.

Technical breakdown

Delegation chains and scope creep in AI agent identity

Delegation chains describe a sequence where one identity hands work to another, which then calls APIs or downstream services on its behalf. The risk is that original intent gets diluted at every hop, especially when downstream systems inherit broader permissions than the initiating task required. In agentic environments, this is not simply overprovisioning. It is identity drift across runtime actions, where the system ends up acting with more authority than any single actor should possess.

Practical implication: enforce a strict rule that every handoff preserves or reduces scope, never expands it.

RFC 8693 token exchange and one-way deescalation

OAuth token exchange under RFC 8693 is meant to support delegated access without reusing the original bearer token everywhere. The security value comes from one-way deescalation, where each exchanged token carries less privilege than the one before it. That matters for AI agents because token propagation becomes dangerous when an agent can repackage or forward credentials to another agent, service, or workflow step and still retain full authority.

Practical implication: design token exchange so that privilege can only narrow as delegation deepens.

DPoP proof-of-possession for forwarded tokens

DPoP binds a token to a specific cryptographic key, which makes a stolen or relayed token far less useful outside the intended session. In bearer-token models, whoever holds the token can use it. In proof-of-possession models, the token alone is not enough. For agentic systems, that distinction matters because one compromised or over-curious agent should not be able to forward credentials to another component and inherit the same access path.

Practical implication: require proof-of-possession for agent tokens that may traverse multiple services or sub-agents.

Breaches seen in the wild

• Moltbook AI agent keys breach — Moltbook breach exposed 1.5M AI agent keys.
• Salesloft OAuth token breach — hackers stole OAuth tokens to access Salesforce data via Salesloft.

Read our 52 NHI Breaches Analysis report for a comprehensive view of breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Delegation chains are now an identity control problem, not just an application workflow issue. The article shows how each handoff from human to agent to API can stretch the original authorization until it no longer resembles the initiating identity. That means the governance question is not whether delegation is useful, but where the chain becomes ungovernable. Practitioners should treat every extra hop as a new identity boundary.

Monotonic scope reduction is the right concept for agentic identity governance. Permissions should only move downhill because upward drift creates effective privilege escalation even when no malicious actor is present. This reframes least privilege from a provisioning-time statement into a runtime rule about how authority can move across agent interactions. Practitioners need a model that forbids privilege growth between delegation steps.

Proof-of-possession closes the token relay failure mode that bearer models cannot stop. If a token can be forwarded and reused elsewhere, the identity control is too weak for agentic execution chains. DPoP changes the security boundary from possession of a string to possession of the corresponding key, which is much harder to relay across agents or services. Practitioners should view token relay as an identity design flaw, not a mere abuse case.

Agentic sandboxes create the only realistic way to test escalation behaviour before production exposure. The article is right to frame simulation as a control, because escalation attempts, delegation cascades, and scope creep are emergent behaviours that static review rarely reveals. A named concept here is identity blast radius: the distance a single agent decision can travel before the organisation notices. Practitioners should measure that blast radius before deploying more autonomy.

Autonomous helper behaviour invalidates the assumption that identity follows a fixed, reviewable path. Least privilege was designed for a condition where the actor's effective authority is knowable at issuance and stable long enough to certify. That assumption fails when an agent can dynamically chain requests, relay tokens, and alter its own reach mid-session. The implication is that access governance must be evaluated against runtime behaviour, not just entitlements at creation.

From our research:

• 80% of identity breaches involved compromised non-human identities such as service accounts and API keys, according to Ultimate Guide to NHIs.
• 97% of NHIs carry excessive privileges, increasing unauthorised access and broadening the attack surface.
• 52 NHI Breaches Analysis shows how over-scoped machine identities repeatedly turn routine access into breach paths.

What this signals

Identity blast radius: agent programmes should now be measured by how far a delegated action can travel before controls stop it. If the chain can expand privilege faster than it can be certified, the operating model is already behind the risk.

With 97% of NHIs carrying excessive privileges, per Ultimate Guide to NHIs, the issue is not whether agentic access will drift, but how quickly your programme can detect and constrain that drift.

The practical shift is to treat sandbox testing, token binding, and delegation policy as part of identity governance, not as optional engineering controls. That is where agentic IAM becomes operationally real.

For practitioners

• Enforce downhill delegation rules Require every agent-to-agent or agent-to-service handoff to preserve or reduce privilege. Block any exchange that introduces broader scope than the initiating task needs, including hidden privilege expansion through downstream APIs.
• Bind delegated tokens to possession Use proof-of-possession for agent credentials so that forwarded tokens cannot be replayed by another agent or service. Treat bearer-style reuse as a design exception, not a default.
• Simulate escalation paths before release Test delegation cascades, token relay attacks, and scope interpreter failures in a sandbox that mirrors production permissions. Use the results to find where agents can bypass intended boundaries before they do it live.
• Review every hop in the delegation chain Map the full path from human request to final API call and identify where identity stops being recognizable. Remove any service that inherits broader access than its role requires and document the expected scope at each hop.

Key takeaways

• AI agent risk emerges when delegation chains expand authority beyond the original request, turning routine workflows into identity drift.
• Token relay and scope creep are the main failure modes here, which is why proof-of-possession and one-way deescalation matter.
• The right control posture is to simulate escalation before production, then enforce privilege reduction at every hop in the chain.

Key terms

• Delegation Chain: A delegation chain is the sequence of identities, services, or agents that pass a task and its authority from one step to the next. In agentic systems, the chain matters because privilege can change at each hop, creating access that is broader than the original request if controls are weak.
• Monotonic Scope Reduction: Monotonic scope reduction means every delegated step must keep the same permissions or narrow them further. It is a runtime security rule for non-human and autonomous identities, designed to stop privilege from growing as tasks move through agents, services, and APIs.
• Proof-of-Possession Token: A proof-of-possession token is bound to a specific cryptographic key, so the token alone cannot be reused by another party. For agentic identity, this reduces the value of relay attacks because forwarding the token without the matching key does not grant access.
• Identity Blast Radius: Identity blast radius is the amount of damage or lateral reach a single identity decision can create before detection or containment. For AI agents, it describes how far delegated authority can spread across services when scope, binding, and review controls are too weak.

Deepen your knowledge

Agentic delegation, token binding, and scope reduction are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are designing controls for AI agents that call downstream services, it is worth exploring.

This post draws on content published by Strata Identity: Agentic sandboxing and downhill delegation for AI agent identity. Read the original.