---
id: CVE-2026-76187
title: >-
  Apache Airflow Keycloak provider: the unauthenticated token endpoint accepts a
  client-credentials grant for any confidential client registered in the
  Keycloak realm, not only the client configured for Airflow
summary: >-
  Apache Airflow Keycloak provider: the unauthenticated token endpoint accepts a
  client-credentials grant for any confidential client registered in the
  Keycloak realm, not only the client configured for Airflow. No allowlist
  restricts whic…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-287
vendor: apache
product: apache-airflow-providers-keycloak
affected:
  - apache-airflow-providers-keycloak < 0.10.0
patched:
  - apache-airflow-providers-keycloak 0.10.0
published: '2026-09-16'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T14:27:16.527'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76187'
references:
  - url: 'https://github.com/apache/airflow/pull/72205'
    label: security@apache.org
  - url: 'https://lists.apache.org/thread/5cqh5ojl3718ogb0q1dcd9vdr47z7gp3'
    label: security@apache.org
  - url: >-
      https://lists.apache.org/thread/j1b9ddljxphqvoc41z7gthj4zh34vmlw?users@airflow.apache.org
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/09/15/9'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
epss: 0.0095
epssPercentile: 0.59772
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-17T19:21:36.545412Z'
ingestedAt: '2026-09-16T09:53:11.607Z'
---

## Overview

Apache Airflow Keycloak provider: the unauthenticated token endpoint accepts a client-credentials grant for any confidential client registered in the Keycloak realm, not only the client configured for Airflow. No allowlist restricts which client ids may authenticate, so the credentials of an unrelated application that happens to share the realm are valid Airflow login credentials, and Airflow mints a signed session token for that application's service account. The endpoint also answers unauthenticated credential guesses against Keycloak under Airflow's identity.

Affects deployments using the Keycloak auth manager whose realm is shared with other confidential clients. The attacker needs valid credentials for any one of those clients, not for Airflow. Resource authorization is still evaluated per subject, so the access gained is whatever that service account holds, plus any endpoint gated only on being authenticated.

Users of apache-airflow-providers-keycloak are recommended to upgrade to version 0.10.0 or later, which accepts only the configured client on that grant.

## Affected

- `apache-airflow-providers-keycloak < 0.10.0`

## Remediation

Upgrade past the affected range:

- `apache-airflow-providers-keycloak 0.10.0`