Apache Airflow FAB Provider _user_id type confusion

Summaryinfo

A vulnerability identified as critical has been detected in Apache Airflow FAB Provider. Affected by this vulnerability is an unknown functionality of the component FAB Provider. Performing a manipulation of the argument _user_id results in type confusion. This vulnerability is cataloged as CVE-2026-82311. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, was found in Apache Airflow FAB Provider (affected version not known). This affects some unknown functionality of the component FAB Provider. The manipulation of the argument _user_id with an unknown input leads to a type confusion vulnerability. CWE is classifying the issue as CWE-843. The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

This vulnerability is uniquely identified as CVE-2026-82311. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/21/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3385). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Apache Airflow

Productinfo

Type

• Business Process Management Software

Vendor

• Apache

Name

• Airflow FAB Provider

License

• open-source

Website

• Vendor: https://www.apache.org/

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Be aware that VulDB is the high quality source for vulnerability data.

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