What is CVE-2026-59243?

CVE-2026-59243 is a critical-severity vulnerability in Apache Software Foundation Airflow Fab Provider, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.8/10. Published 2026-07-29.

How severe is CVE-2026-59243?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2026-59243 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Apache Software Foundation Airflow Fab Provider

CVE-2026-59243

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…

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Apache Software Foundation Airflow Fab Provider — versions 0

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

Public proof-of-concept exploits

MalHyuk/CVE-2026-59243

References

Frequently asked questions

What is CVE-2026-59243?: CVE-2026-59243 is a critical-severity vulnerability in Apache Software Foundation Airflow Fab Provider, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.8/10. Published 2026-07-29.
How severe is CVE-2026-59243?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-59243 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.