The policy layer that determines who can pull or inspect container manifests and layers through the Open Container Initiative API. Effective control must apply to protocol endpoints, not just the user interface, because Docker clients interact directly with the registry API.
Expanded Definition
OCI registry access control is the policy layer that governs whether a non-human identity can pull, list, or inspect container artifacts through the registry API. In practice, it is not enough to secure the web console, because Docker clients and CI/CD systems speak directly to the API endpoints and can bypass assumptions built around human workflows.
For NHI security, the term covers repository-level permissions, token scope, service account bindings, and the ability to separate read-only discovery from image retrieval. The control becomes especially important where registry access is tied to automated build pipelines, ephemeral agents, and mirrored registries. Guidance varies across vendors on how finely access can be scoped, so organisations should treat the registry as an identity enforcement point rather than a storage bucket. The OWASP Non-Human Identity Top 10 and NIST SP 800-53 Rev 5 Security and Privacy Controls both reinforce the need to constrain privileged access at the resource boundary, not merely at login.
The most common misapplication is assuming registry UI permissions protect the API, which occurs when teams grant broad tokens to build tooling and never review endpoint-level scope.
Examples and Use Cases
Implementing OCI registry access control rigorously often introduces pipeline friction, requiring organisations to weigh faster builds against tighter artifact governance.
Common uses include:
- A CI runner gets read-only access to pull approved base images but cannot enumerate private repositories.
- A deployment agent can inspect manifest metadata for promotion checks, while release engineers retain separate write permissions.
- A platform team scopes registry tokens per namespace so one application team cannot discover another team’s images or tags.
- A security scanner is allowed to fetch layers for inspection, but its credentials expire quickly and cannot be reused interactively.
- A mirror registry receives controlled replication rights, reducing blast radius if the upstream token is compromised.
These patterns align with NHI governance lessons from the Ultimate Guide to NHIs and the incident patterns described in Massive Docker Hub Secrets Leak. They also map cleanly to registry governance concepts in CIS Controls v8, where access should be limited to authorized assets and monitored continuously.
Why It Matters in NHI Security
OCI registry access control is a high-value control because registry credentials often become reusable footholds for image theft, tampering, and supply-chain injection. Once a token can pull sensitive artifacts, an attacker may be able to copy proprietary code, extract embedded secrets, or replace trusted images with malicious ones if write access is also exposed. In NHI environments, that risk is amplified because registry access is usually machine-driven, long-lived, and embedded in build automation.
NHIMG research shows that only 5.7% of organisations have full visibility into their service accounts, which makes it difficult to know which identities can reach registry endpoints in the first place. The same visibility gap is why registry tokens are frequently overlooked during access reviews, even when broader IAM reviews exist. Strong registry controls also support the intent of ISO/IEC 27001:2022 Information Security Management by reducing unauthorized exposure of sensitive assets and limiting the blast radius of compromised automation.
Organisations typically encounter the true scope of registry access control only after a leaked token, unexpected image pull, or tampered deployment reveals that artifact access was broader than anyone believed.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST CSF 2.0, NIST SP 800-63, NIST Zero Trust (SP 800-207) and NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-05 | Covers excessive privileges and weak lifecycle handling for non-human identities. |
| NIST CSF 2.0 | PR.AC-4 | Addresses access permissions and least-privilege enforcement for system resources. |
| NIST SP 800-63 | AAL2 | Identity assurance concepts inform strength expectations for service credentials and tokens. |
| NIST Zero Trust (SP 800-207) | AC-4 | Zero Trust requires resource-level policy enforcement instead of implicit network trust. |
| NIST AI RMF | Risk management guidance applies where automated agents use registry credentials and artifacts. |
Enforce policy at the registry endpoint and verify every client request before granting artifact access.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on August 18, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
