Scopes are permission-oriented strings that represent the access a client is asking for, while claims are statements about an entity and its attributes. Scopes are used to request and control access, including access to claims. Claims describe identity data that can be trusted and consumed by authentication and authorization systems.
How scopes and claims differ in practice
Scopes and claims solve different problems in OAuth and OpenID Connect. A scope is a request for what a client wants to do, usually framed around access to an API or protected resource. A claim is information about an entity, usually the user or client, that is asserted in a token and later consumed by a relying party or authorization decision.
The cleanest way to think about it is that scopes shape the access request, while claims shape the identity or attribute data carried by the protocol. In OAuth, scopes are central to delegated access. In OpenID Connect, claims are central to who the subject is and what attributes the provider is willing to release.
That distinction matters because the same token can contain both. For example, a client may request an OpenID Connect scope that triggers the inclusion of identity claims, but the scope itself is still the permission request. The claims are the returned statements, such as subject identifier, email, name, or assurance-related attributes, depending on what the provider releases.
How each one is used by OAuth and OpenID Connect
OAuth uses scopes as a consent and authorization control. They help the authorization server decide whether the client should receive a token, and they help the resource server decide whether that token is sufficient for the requested action. If the token lacks the needed scope, access should fail even if the token is otherwise valid.
OpenID Connect adds identity layer semantics on top of OAuth, so claims become the main way identity data is conveyed. The ID token and userinfo response can carry claims about the authenticated subject, but those claims should be treated as protocol output, not as a substitute for authorization logic. A claim that a user is an employee, for example, may inform policy, but it does not by itself grant access.
This is why scope and claim design should be separated. Scopes should be coarse enough to remain understandable and consentable, while claims should be limited to the data the client actually needs. Overloading scopes with identity meaning, or treating claims as permissions, usually leads to confusing integrations and weak policy decisions.
For protocol context, the relationship is defined in the core OAuth 2.0 framework and in OpenID Connect Core 1.0, which layers authentication and identity claims on top of OAuth-based authorization.
Where confusion creates security and integration problems
Confusing scopes and claims often leads to either over-collection of identity data or over-permissioned access. A client may ask for broad scopes because the implementer thinks they are “just labels,” when in fact they control access. Or a team may start relying on claims as if they were entitlements, even though claims are assertions that can change across issuers, tenants, or token types.
Another common failure is assuming that a claim in an ID token is enough to authorize API access. In practice, an ID token is about authentication to the client, while access to APIs should be governed by access tokens and the scopes or audience controls attached to them. Mixing those roles can create confused-deputy problems, brittle integrations, and excessive trust in identity assertions.
Scoped access is also safer when the request is explicit about the target resource. Resource indicators and audience restriction help keep scopes tied to the right API, reducing token misuse if a token is replayed or presented to the wrong service. Claims remain useful, but they should support policy and session context rather than substitute for resource-level checks.
For practical guidance on the permission side of the model, OAuth Scope Design Guide is the clearest internal companion for designing scopes that are narrow, meaningful, and enforceable.
Risk and Threat Considerations
Scope and claim confusion can create both privilege creep and trust confusion. If an implementation grants access based on claims that were never meant to authorize actions, or if it issues broad scopes because the requesting party is overtrusted, the result is a wider blast radius than the business intended.
Failure mechanism: Weak separation between identity assertions and access decisions lets attackers exploit overbroad scopes, stale claims, or misinterpreted token contents to reach resources they should not control.
Impact: The likely outcomes are overexposed APIs, unintended data disclosure, policy bypass, and harder incident response because teams cannot tell whether misuse came from the scope grant, the claim content, or the downstream enforcement layer.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-53 Rev 5 and OWASP ASVS set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | Scopes and claims depend on secure token and credential lifecycle. |
| AC-6 — Least Privilege | Scope design is a least-privilege authorization problem for OAuth access. | |
| IA-2 — Identification and Authentication (Organizational Users) | OIDC claims carry identity assertions that depend on authentication strength. | |
| Recommendation — Manage token and secret lifecycles so scopes are not overissued or reused after trust changes. Limit scopes to the minimum access needed for each client and resource. Require strong authentication before accepting identity claims for session creation. | ||
| OWASP ASVS | V10 — OAuth and OIDC | OAuth scopes and OIDC claims are core protocol mechanisms under verification. |
| V8 — Authorization | Scopes govern what access a client is authorized to obtain. | |
| Recommendation — Verify scope handling, token contents, and claim use separately in OAuth/OIDC implementations. Enforce authorization at the resource and function level rather than trusting token text alone. | ||
Practitioner Guidance
What to verify: Check whether your authorization server, token consumer, and API gateway all agree on the meaning of each scope, and whether claims are being used only as trusted attributes, not as stand-alone permissions. If a team cannot explain where authorization ends and identity assertion begins, the design is usually too loose.
Decision rule: If the question is “may this client do X?”, look at scopes and resource enforcement. If the question is “who is this subject and what attributes are asserted about it?”, look at claims. If the answer depends on both, keep the policy layers separate and make the API validate access independently of any identity data in the token.
Practitioner takeaway: Treat scopes as the contract for requested access and claims as the contract for asserted identity data. The safest implementation is one where scopes drive authorization and claims only enrich trusted context.
Related resources from NHI Mgmt Group
- Guide: OAuth 2.0 and OpenID Connect Guide for Identity Teams
- OpenID Connect Scopes and Claims
- What is OpenID Connect (OIDC) and how does it extend OAuth 2.0 for NHIs?
- Why does JWE matter in OAuth and OpenID Connect flows?
- Why do OAuth and OpenID Connect integrations create IAM risk even when they reduce password use?
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Reviewed and updated by the NHIMG editorial team on October 30, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org