CVE-2026-76186: Apache Airflow Keycloak provider: Keycloak token cookies not bound to Airflow session identity

[Vincent Beck <vincbeck () apache org>]

Severity: moderate 

Affected versions:

- Apache Airflow Keycloak provider (apache-airflow-providers-keycloak) before 0.10.0

Description:

Apache Airflow Keycloak provider: from Airflow 3.3 the Keycloak auth manager takes a user's identity from the signed 
Airflow session token but takes the Keycloak access and refresh tokens used for every authorization decision from 
separate, unauthenticated cookies, and never checks that the two describe the same subject. A user who holds any valid 
Airflow login of their own, together with another subject's Keycloak access or refresh token obtained out of band, can 
pair the two: Airflow then authorizes requests with the foreign token's privileges while the session identity, audit 
log and cache keys continue to name the attacker's own account. The refresh path re-issues an Airflow session token for 
the original identity carrying the foreign tokens, so the mismatched pairing survives across sessions.

Affects deployments running Airflow 3.3 or later with the Keycloak auth manager. Earlier versions carried the Keycloak 
tokens inside the signed session token, so the binding existed and was lost when they moved into separate cookies.

Users of apache-airflow-providers-keycloak are recommended to upgrade to version 0.10.0 or later, which binds the 
cookie-supplied tokens to the session identity.

Credit:

Claude Security Scans (tool)
Jarek Potiuk (remediation developer)

References:

https://github.com/apache/airflow/pull/72207
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-76186