CVE-2026-59243: Apache Airflow FAB provider · Improper Verification of Cryptographic Signature
Affects Apache Airflow FAB providerSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical : upgrade to 3.7.3 as a priority.
Data as of 28 Oct 2026, 05:11 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.7.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Apache Airflow FAB provider to 3.7.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software FoundationApache Airflow FAB provider | Affected
| Fixed in
|
AI-suggested
A patch is available in `apache-airflow-providers-fab` version 3.7.3, which changes the default setting to verify cryptographic signatures on ID tokens (`verify_signature=True`). Users should upgrade to version 3.7.3 or later to remediate this vulnerability. Since this is a cloud service component, the vendor manages remediation for cloud-hosted deployments; users should verify their environment is updated accordingly.
Description
The FAB auth manager's Azure AD OAuth login defaulted `verify_signature=False` when decoding the ID token, so an attacker able to present a forged or unsigned (`alg:none`) ID token to the OAuth callback could bypass authentication and log in as an arbitrary user, including one holding the Admin role (CWE-347). Deployments running the FAB auth manager with the Azure AD OAuth login path under its default configuration are affected; the Authentik path already defaulted to `True`. This issue affects `apache-airflow-providers-fab` before 3.7.3. Users are advised to upgrade to `apache-airflow-providers-fab` 3.7.3, which defaults `verify_signature=True`.