External risk intelligence

Apache Airflow FAB Session Invalidation Flaw Allows Persistent Access

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-82311

Apache Airflow is commonly deployed as a web-based workflow orchestration platform accessible over the network. The vulnerability resides within the Flask-AppBuilder (FAB) authentication provider used by Airflow to manage user sessions, which is typically exposed via the web interface to administrators and users.

Apache Airflow Providers Fab

2.4.2 to before 3.9.0

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory concerns a vulnerability in the Apache Airflow FAB provider where resetting a user's password does not correctly invalidate their existing sessions. This means an attacker holding a compromised session cookie can maintain access even after the password has been changed, potentially bypassing security containment actions.

Password resets may not end active user sessions.
Compromised sessions remain active post-reset.
Confirm exposure and ensure timely upgrades.

Attack Path

How an attacker could exploit the issue

An attacker can maintain access to a victim's account even after their password has been reset, provided the attacker already possesses a copy of the victim's session cookie. This occurs because the system fails to properly invalidate existing database-backed sessions when a password reset is initiated. The vulnerability is present when the FAB auth manager is configured to use a database for session storage. This allows an attacker to retain unauthorized access to a user's account, bypassing the intended security measure of a password reset.

Victim's session cookie must be compromised.
Password reset command is executed.
Attacker keeps unauthorized access.

Live Threat

Current exploitation, exposure, and threat context

When the FAB auth manager uses a database-backed session, resetting a user's password does not invalidate their existing session cookies. This means an attacker who has already stolen a user's session cookie can maintain access to that user's account even after the password has been changed.

Existing user sessions are at risk.
Stolen session cookies enable continued access.
Unwanted access persists after password reset.

Operational Fix

Recommended remediation, mitigation, and detection steps

For deployments using the FAB auth manager with `[fab] session_backend=database`, the platform or application owner is responsible for addressing this vulnerability. The initial step is to identify all instances of the affected Airflow FAB provider, confirm their accessibility and business criticality, and then coordinate remediation with the vendor based on the assessed risk.

Platform/application owners should investigate.
Verify session backend configuration and reachability.
Plan upgrade during the next maintenance window.

Supplementary metadata

CVSS vector

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Frequently asked questions

What is the apache-airflow-providers-fab package?

This software component is an authentication provider for Apache Airflow, a platform used to orchestrate complex data workflows. It integrates Flask-AppBuilder (FAB) to handle user identities, logins, and session management within the Airflow web interface, ensuring that the correct users can access or manage data pipelines.

How does CWE-613 relate to CVE-2026-82311?

The vulnerability is a form of insufficient session expiration, classified as CWE-613. In this case, the system fails to properly invalidate or delete active sessions stored in the database when a password is reset. Because the software uses an incorrect identifier to match sessions during the cleanup process, the old session remains active and valid for an unauthorized user.

When does this session handling error trigger?

The bug occurs when an administrator or user triggers a password reset while using the database-backed session configuration. It does not affect installations using secure-cookie backends, as those are not designed for central session invalidation. The failure specifically happens because the backend code compares mismatched data types—a string versus an integer—preventing the session from being successfully cleared.

Is my instance at risk according to Halo Surface Signal?

Halo Surface Signal indicates that Apache Airflow is commonly deployed as a web-accessible platform. If your instance is reachable over a network, the risk is higher because the authentication provider is typically exposed through the web interface. Because the flaw allows an attacker to maintain persistence via a stolen cookie, any deployment accessible via the network should be considered for review.

How do I address this CVE-2026-82311 vulnerability?

The primary response is to update the apache-airflow-providers-fab package to version 3.9.0 or later. This update fixes the logic error by ensuring the system correctly matches identifiers to invalidate sessions. If you cannot upgrade immediately, verify your session backend configuration and prioritize the update during your next maintenance cycle to restore secure session control.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.