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OpenAdvisories
Medium · 4.6 CVE-2026-114619 EUVD-2026-108521GHSA-q686-2qmg-hqc7PYSEC-2026-4359

Authlib: OpenID implicit grant checks raw scope instead of allowed scope before issuing ID tokens

Published Oct 22, 2026 · Updated Oct 29, 2026 · Assigned by GitHub_M

Description

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 products

VendorProductAffectedFixed
authlib authlib < 1.9.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 python-authlib 1.9.1-1 —
Debian 13 python-authlib No fix yet —
Debian 12 python-authlib No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 python-authlib No fix yet —
Show 3 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 26.04 LTS python-authlib No fix yet —
Ubuntu Pro 24.04 LTS python-authlib No fix yet —
Ubuntu Pro 22.04 LTS python-authlib No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed python-Authlib 1.9.1-1.1 openSUSE-SU-2026:12390-1

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling open-webui 0.12.3-r11 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI authlib < 1.9.0 1.9.0 GHSA-q686-2qmg-hqc7

Advisories 1

References