---
id: CVE-2026-114619
title: >-
  Authlib: OpenID implicit grant checks raw scope instead of allowed scope
  before issuing ID tokens
summary: >-
  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 …
severity: medium
cvss: 4.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-863
vendor: authlib
product: authlib
affected:
  - authlib < 1.9.0
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T21:31:02.929Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114619'
references:
  - url: 'https://github.com/authlib/authlib/security/advisories/GHSA-q686-2qmg-hqc7'
    label: 'https://github.com/authlib/authlib/security/advisories/GHSA-q686-2qmg-hqc7'
  - url: 'https://github.com/authlib/authlib/pull/945'
    label: 'https://github.com/authlib/authlib/pull/945'
  - url: >-
      https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf
    label: >-
      https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf
  - url: 'https://github.com/authlib/authlib/releases/tag/v1.9.0'
    label: 'https://github.com/authlib/authlib/releases/tag/v1.9.0'
tags:
  - cve.org
ingestedAt: '2026-10-22T22:00:50.448Z'
---

## Overview

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 < 1.9.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.