Zero trust implementation is still undermined by permission creep

At a glance

What this is: Axiad’s guidance says zero trust is undermined when permission creep lets access expand beyond job need after initial authentication and device checks.

Why it matters: IAM, PAM, and NHI teams need to treat permission drift as a governance failure, because zero trust depends on continuously enforcing least privilege across human and non-human access paths.

Context

Zero trust assumes access is never trusted by default, but that assumption fails if entitlements are allowed to accumulate after the first authentication event. In practice, permission creep turns a continuous verification model into a one-time gate with stale access left behind.

The article frames zero trust as a mix of technology and operating model, with MFA, device verification, encryption, access limitation, and monitoring all playing a role. The governance gap is that periodic reviews often lag the rate at which access expands, especially in environments with human users and non-human identities sharing the same control plane.

Key questions

Q: What breaks when permission creep is not controlled in a zero-trust programme?

A: The model stops being dynamic and becomes a new wrapper for old standing access. Privileges accumulate, access reviews turn into paperwork, and teams lose the ability to prove that the current entitlement set matches current need.

Q: Why do MFA and device checks not prevent overprivileged access?

A: MFA and device verification strengthen the decision to let someone in, but they do not automatically limit what that identity can do after entry. If permissions are inherited, accumulated, or never removed, the user or workload can still operate with excessive authority. Zero trust needs both strong authentication and active authorization governance.

Q: How do organisations know if zero trust controls are actually working?

A: They know the controls are working when they can inventory privileged identities, prove access is time-bound, and show that rotation and revocation happen on schedule. A healthy programme also has few manual exceptions and low workflow friction, because recurring bypasses are a sign that policy and operations are out of sync.

Q: Should organisations review human and non-human access with the same zero trust discipline?

A: Yes. The governance question is not whether the subject is a person or a machine, but whether access still matches current business need. Service accounts, API keys, and human users all create risk when entitlement drift is ignored. The review model should be adapted to the actor type, but the control objective is the same.

Technical breakdown

Why permission creep breaks zero trust enforcement

Permission creep is the gradual expansion of access beyond what a role or task requires. In zero trust, that matters because the model assumes every access request is evaluated in context, not granted indefinitely after initial approval. If entitlements are not revalidated, the system may authenticate identity correctly while still allowing overbroad access. That is a governance failure, not an authentication failure. The core problem is not whether the first login was strong, but whether the access granted at login still reflects current need, device state, and policy intent.

Practical implication: treat entitlement drift as a zero trust control failure and review access on a recurring, risk-based schedule.

MFA and device verification do not solve entitlement drift

MFA and device checks strengthen entry assurance, but they do not answer the separate question of what the identity can do once inside. Zero trust is commonly implemented as a front-door control, yet the article shows that over time the real weakness is authorization sprawl. That is why least privilege and access review remain essential alongside authentication. A strong sign-in flow can coexist with weak authorization boundaries if users keep inherited, temporary, or accumulated permissions long after they are needed.

Practical implication: pair strong authentication with entitlement governance so that sign-in assurance does not mask overprivileged access.

Monitoring must look for access growth, not only suspicious logins

Monitoring in a zero trust programme is often framed around anomalous access attempts, but permission creep creates a quieter failure mode. The issue is not just an attack event, but a slow increase in standing access that makes the identity more powerful than intended. That requires entitlement visibility, change tracking, and access review evidence, not only detection of unusual login behaviour. For NHIs and users alike, zero trust only works when access scope is measured as carefully as access success.

Practical implication: add entitlement drift signals to monitoring so overprivilege is visible before it becomes a breach path.

Threat narrative

Attacker objective: Exploit accumulated access to reach sensitive systems or data that should no longer be available to the identity.

1. Entry occurs through a valid authentication event, often strengthened by MFA or device verification, so the identity is accepted at the front door.
2. Escalation happens gradually as additional permissions are granted, inherited, or left in place after role changes, creating permission creep.
3. Impact follows when the overextended identity can reach data or systems beyond its current business need, weakening zero trust containment.

Breaches seen in the wild

• Co-op cyber attack 2025: Attackers linked to Scattered Spider tricked their way into a Co-op employee account and stole personal data of all 6.5 million members.

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

Permission creep is the point where zero trust becomes procedural instead of real: A programme can authenticate users and devices correctly while still leaving stale entitlements in place. That is a governance defect, because zero trust is only meaningful when access is continuously re-justified, not merely initially approved. The practitioner conclusion is simple: if privilege growth is not monitored, zero trust degrades into perimeter thinking with better login screens.

Least privilege is not a provisioning event, it is a lifecycle condition: The article’s logic shows that access must stay aligned to current role, task, and device posture over time. This is why JML, access review, and PAM governance matter inside zero trust programmes, not beside them. The practitioner conclusion is that entitlement ownership must be operational, or overpermission will outrun policy.

Identity attack surface expansion: Permission creep expands the number of actions an identity can perform even when the authentication control remains intact. For human users that means role sprawl; for NHIs it means persistent entitlement drift and unused permissions that widen blast radius. The practitioner conclusion is that reducing attack surface requires shrinking access scope continuously, not only hardening entry controls.

Zero trust depends on proving access still fits the current context: MFA, encryption, and device checks are necessary, but they do not answer whether the identity should still hold the permissions it has accumulated. That assumption was designed for static access models and fails when business change is constant. The practitioner conclusion is to treat authorization review as the control that validates the whole zero trust model.

Continuous verification must extend beyond authentication into authorisation: The article reinforces a broader market signal that teams are moving from single-factor trust decisions toward ongoing access governance. That shift is especially relevant where human and non-human identities share the same identity fabric. The practitioner conclusion is that zero trust maturity should be measured by entitlement churn control, not by login friction alone.

From our research library:

• 90% of IT leaders say properly managing NHIs is essential for a successful zero-trust implementation, according to the Ultimate Guide to NHIs.
• By 2029, 40% of enterprises that successfully implement zero trust within cloud service provider environments will rely on the advanced visibility and control capabilities offered by CNAPP solutions.
• Read next: Zero Trust Identity Guide

What this signals

Identity attack surface expands when permission creep is left to accumulate: The practical issue is not only who authenticated successfully, but how far that identity can later move inside the environment. Zero trust programmes should measure whether access scope is staying aligned to task need across human and non-human identities, because authorization drift is what quietly defeats the model.

Continuous review has to reach service accounts as well as users: A zero trust design that only governs interactive logins misses the identities most likely to retain excess access. That is why entitlement governance, offboarding, and privilege review need to be applied across the full identity estate, not only the workforce population.

For practitioners

• Audit entitlement growth paths Map where access expands over time through role change, group inheritance, temporary elevation, and manual exceptions. Focus on the identities most likely to accumulate permissions without a formal owner reviewing them.
• Tie access reviews to access drift Schedule recertification around entitlement changes rather than fixed calendar habits alone. Review whether the current access still matches job function, device posture, and data sensitivity.
• Separate authentication from authorisation Treat MFA and device checks as entry controls, then assess whether authorization boundaries still match least privilege after sign-in. Do not assume strong login controls compensate for broad permissions.
• Track non-human entitlement creep Apply the same access review discipline to service accounts, API keys, and automated workflows so machine access does not become permanently broader than its task requires.
• Use monitoring to flag access expansion Look for increases in group membership, privilege scope, and data reach as part of routine monitoring so overpermission is visible before it becomes exploitable.

Key takeaways

• Permission creep is the quiet failure mode that can make a zero trust programme look healthy at the front door while leaving excessive access in place.
• The article’s core message is that MFA, device checks, and encryption are necessary but insufficient if authorization drift is not controlled over time.
• Teams need recurring entitlement review and lifecycle governance across both human and non-human identities if zero trust is meant to reduce real attack surface.

Key terms

• Permission Creep: The gradual accumulation of access beyond what a user or workload currently needs. It usually happens because initial approvals are never fully removed or recertified. In practice, permission creep is a lifecycle failure that turns temporary exception access into de facto standing privilege.
• Least Privilege: A security principle requiring that every identity, human or non-human, is granted only the minimum permissions necessary to perform its function. Least privilege is the single most effective control for reducing NHI blast radius.
• Zero Trust: A security model that assumes no identity, human or non-human, should be trusted by default, even inside a network perimeter. Every access request must be verified, authorised, and continuously validated.
• Entitlement review: A governance process that checks whether users, service accounts or systems still need their access. For modern identity programmes, the limitation is timing: if reviews happen too late or too rarely, access may already have been misused before the review occurs.

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