Zero trust implementation is still undermined by permission creep

At a glance

What this is: Axiad’s post explains how zero trust is implemented through MFA, device verification, encryption, least privilege, monitoring, and periodic access reviews, with permission creep called out as a key failure mode.

Why it matters: It matters because the same trust assumptions that weaken human IAM also undermine NHI governance and any future autonomous access model if verification is not continuous.

By the numbers:

• Only 5.7% of organisations have full visibility into their service accounts.
• 97% of NHIs carry excessive privileges, increasing unauthorised access and broadening the attack surface.
• 80% of identity breaches involved compromised non-human identities such as service accounts and API keys.

👉 Read Axiad's guide on implementing zero trust in business environments

Context

Zero trust is an identity and access model that assumes no user, device, or workload is inherently trustworthy. In practice, that means access decisions must be verified at the point of use, not granted once and forgotten. For IAM teams, the challenge is that older perimeter-first thinking still shapes many control sets, especially where service accounts and privileged access have been left outside the same review discipline as human users.

The post frames zero trust through a familiar practitioner problem: access expands over time unless it is deliberately constrained. That issue matters across human IAM, NHI governance, and emerging autonomous access patterns because all three fail when entitlement is treated as static. The result is permission creep, weak posture checks, and policy drift across systems that were never designed for continuous verification.

Key questions

Q: How should security teams implement zero trust without creating more user friction?

A: Start with the highest-risk access paths and make verification proportional to sensitivity. Use MFA, device posture checks, and least privilege for critical systems first, then expand to broader populations. The aim is not more prompts, but fewer unnecessary trust assumptions across human and non-human access.

Q: Why do service accounts and API keys complicate zero trust?

A: Because they do not behave like human users, yet they often carry persistent access into cloud and application environments. If teams only verify people at login, machine identities can bypass the spirit of zero trust through standing credentials, weak ownership, or poor offboarding.

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: Who is accountable when zero-trust controls fail to reduce access over time?

A: Accountability sits with the identity, access, and application owners who define trust rules and with the governance function that recertifies them. If elevated access persists unchecked, the failure is usually in ownership, review cadence, or enforcement rather than in a single technical control.

Technical breakdown

MFA as a trust gate, not a complete zero-trust model

Multi-factor authentication adds a second or third verification factor before access is granted, but it only answers the question of who or what is presenting credentials at that moment. Zero trust goes further by evaluating context, device posture, session behaviour, and access scope continuously. MFA is necessary when identity spoofing is a concern, but it does not stop over-privileged access, reused sessions, or later misuse after authentication. In identity programmes, MFA should be treated as one control inside a broader access decision chain, not the model itself.

Practical implication: pair MFA with device checks, session controls, and least-privilege entitlements so the trust decision does not end at login.

Permission creep and access review failure modes

Permission creep occurs when users accumulate access that no longer matches their role or task. In zero-trust terms, that is a governance failure because the control assumes access is reviewed and reduced before it becomes risky. Periodic access review helps, but only if entitlement data is accurate and the review process reaches all identities, including service accounts and delegated accounts. If reviews are incomplete or too infrequent, privilege drift becomes normal rather than exceptional, and the model quietly reverts to standing access with a new label.

Practical implication: map every entitlement to an owner and review cycle, then remove stale access before it becomes the default state.

Device verification and encrypted data paths

Zero trust depends on verifying both the actor and the device or workload they are using. That is why device posture, approved device states, VPN or secure access pathways, and encryption are paired controls. Encryption protects data if a device or transfer path is compromised, while device verification reduces the chance that a hostile or unmanaged endpoint is treated as trusted. For non-human identities, the equivalent problem is unmanaged workload context, where credentials move through systems without the same posture checks humans receive.

Practical implication: enforce device and workload posture checks before sensitive access is allowed, especially for remote, cloud, and delegated access paths.

Breaches seen in the wild

• Cisco DevHub NHI breach — IntelBroker exploited exposed Cisco credentials, API tokens and keys in DevHub.
• DeepSeek breach — DeepSeek breach exposed 1M+ log lines and sensitive secret keys.

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

NHI Mgmt Group analysis

Permission creep is the clearest zero-trust failure mode because it turns a dynamic model back into standing privilege. The article correctly treats access review as part of the answer, but the underlying problem is governance drift, not a missing feature. Once access accumulates faster than it is recertified, zero trust becomes a slogan over a legacy entitlement model. The practitioner conclusion is simple: zero trust must be measured by entitlement decay, not policy language.

Zero trust only works when identity verification extends beyond the human login event. The post focuses on MFA and device checks, which are necessary, but modern environments also include service accounts, API keys, and workload credentials that never experience a human login flow. That gap matters because NHI exposure is a recurring breach path, and the same continuous verification logic must reach machine identities as well. The practitioner conclusion is that access assurance has to span every identity type, not just employee sessions.

Least privilege in zero trust is a lifecycle control, not a one-time design choice. The post describes giving users only what they need, but the discipline only holds if provisioning, recertification, and offboarding are all enforced together. In practice, many programmes are strong at initial assignment and weak at removal, which is where risk accumulates. The practitioner conclusion is to treat access minimisation as an ongoing governance process across humans and NHIs.

Continuous verification is the real control plane, and static trust assumptions are the broken premise. Zero trust fails when teams assume a successful authentication or a clean device posture once is enough for the rest of the session. That assumption was designed for perimeter-era networks, not distributed cloud access, third-party delegation, or workload identity. The practitioner conclusion is that identity programmes must be built around continuous state, not one-time approval.

From our research:

• Only 5.7% of organisations have full visibility into their service accounts, according to the Ultimate Guide to NHIs.
• 97% of NHIs carry excessive privileges, which is why access minimisation cannot stop at the human login boundary.
• 52 NHI Breaches Analysis shows how standing credentials and poor offboarding repeatedly turn governance gaps into incidents.

What this signals

Permission creep is the signal that zero trust has started to drift back into legacy access management. If entitlement growth outpaces recertification, the programme is managing access on paper rather than in practice. That is the point where service accounts, shared credentials, and delegated access deserve the same review discipline as employee accounts.

With 91.6% of secrets still valid five days after notification, the operational gap is not just authentication strength, it is persistence after compromise. Teams should treat revocation speed and ownership clarity as first-class zero-trust metrics.

Identity blast radius: the practical measure of how far a compromised identity can move before controls detect or contain it. As zero-trust programmes expand, practitioners should watch whether blast radius is shrinking across human, NHI, and delegated access paths, not just whether login prompts are increasing.

For practitioners

• Map every trust decision to a live control owner Document who owns MFA, device verification, access review, and encryption decisions for each identity class. Include human users, service accounts, and any delegated credentials so no path remains outside the review cycle.
• Remove permission creep before recertification starts to lag Compare current entitlements against job function, workload purpose, or approved use case, then revoke access that no longer has a clear operational need. Prioritise privileged accounts and long-lived credentials first.
• Extend zero-trust checks to non-human identities Apply the same verification discipline to API keys, service accounts, and workload credentials that you use for people. That includes posture validation, scope limits, and routine review of where each credential is used.
• Instrument access review for drift detection Track how often access changes, how long elevated access remains active, and whether reviews result in actual removal. If recertification never removes anything, the process is not governing privilege.

Key takeaways

• Zero trust fails when organisations preserve standing access under a new verification label.
• The biggest control gap is not authentication alone, but incomplete entitlement visibility and review.
• Practitioners should extend zero-trust governance to service accounts, API keys, and delegated access paths.

Key terms

• Zero Trust: A security model that assumes no user, device, or workload is inherently trusted. Access is granted only after verification and should be re-evaluated as context changes. In identity programmes, zero trust is operational only when policy, device state, and entitlement scope are checked continuously.
• 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.
• Device Posture: The security state of an endpoint or workload at the moment access is requested. It includes factors such as managed status, patch level, and policy compliance. Zero trust uses posture to avoid trusting a connection just because credentials are valid.
• Standing Privilege: Access that remains active without a narrow time limit or task scope. It is a common source of excess exposure because it survives long after the original need has passed. In zero trust and NHI governance, standing privilege is what continuous verification is meant to reduce.

Deepen your knowledge

Zero trust implementation, permission creep, and identity verification are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are extending zero trust into service accounts and delegated access, it is worth exploring.

This post draws on content published by Axiad: How to Implement Zero Trust in Your Business. Read the original.