CVE-2026-114619
Authlib: OpenID implicit grant checks raw scope instead of allowed scope before issuing ID tokens
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, OpenIDImplicitGrant.validate_authorization_request() checks the client-controlled raw request.payload.scope for openid after the parent grant has filtered allowed scopes into request.scope. A registered client permitted an ID token response type but not the openid scope can add openid to the request, obtain user consent, and receive a signed ID token containing the user's subject and allowed profile claims. Authorization code flow and deployments that allow openid for every client permitted an ID token response are not affected. In authlib/oidc/core/grants/implicit.py, OpenIDImplicitGrant.validate_authorization_request() checks request.payload.scope instead of the filtered request.scope. This issue is fixed in version 1.9.0.
- Affected
- authlib
- CVSS v3.1 GITHUB
- 4.6 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N - EPSS
- 0.16% chance of exploitation in the next 30 days, 5th percentile
- Published
- 2026-10-22
- Updated
- 2026-10-29
Proof-of-concept exploits (1)
CVE references
- authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedfPATCH
- authlib/authlib/pull/945PATCH
- authlib/authlib/releases/tag/v1.9.0REFERENCE
- authlib/authlib/security/advisories/GHSA-q686-2qmg-hqc7VENDOR