Apache Airflow FAB provider: FAB password reset never invalidates sessions: string/int _user_id comparison is always false

Summary

Apache Airflow FAB provider: resetting a user's password does not delete that user's existing database-backed sessions, despite documented behaviour that it does. The cleanup compares the string identifier Flask-Login stores in the session against the user's integer database identifier, so the comparison never matches and no session is removed. An attacker who already holds a copy of the victim's session cookie keeps access as that user after the password change, so the reset does not evict them. Affects deployments using the FAB auth manager with `[fab] session_backend=database`. The trigger is an administrator (or the user) running the supported password-reset command as a containment action after a session cookie has been compromised; the secure-cookie backend is out of scope, as it documents that it cannot centrally delete sessions. apache-airflow-providers-fab 3.9.0 also fixes CVE-2026-86462, a second, independent route to the same outcome via the Admin user-edit endpoint; a single upgrade closes both. Users of apache-airflow-providers-fab are recommended to upgrade to version 3.9.0 or later, which compares the identifiers consistently.

Timeline

1. Sep 16, 2026, 9:00 AM UTCCVE published
2. Sep 17, 2026, 7:26 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: total

3. Sep 17, 2026, 7:27 PM UTCRecord last updated

Affected versions

• apache-airflow-providers-fab

  From 2.4.2 · fixed in 3.9.0

References 4