CVE-2026-59243
Last modified
CVE-2026-59243 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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`. EPSS estimates a 0.53% chance of exploitation in the next 30 days.
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`.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Apache | Apache-Airflow-Providers-Fab | < 3.7.3 |
References
- https://lists.apache.org/thread/x4784l7z00tl3gw4tv2dmvoon77rxgplMailing List, Vendor Advisory
- http://www.openwall.com/lists/oss-security/2026/07/28/10Mailing List, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-59243?
How severe is CVE-2026-59243?
How do I fix CVE-2026-59243?
How Strix Helps
- Same Subject, Wrong User: A Cross-Issuer Account Takeover in n8nStrix found an identity-binding bug in n8n's token-exchange flow enabling account takeover.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-59236Authorization Bypass Through User-Controlled Key (CWE-639) i…6.9
- CVE-2026-59237Authorization Bypass Through User-Controlled Key (CWE-639) i…6.9
- CVE-2026-59238Stored Cross-site Scripting (CWE-79) in the client-side repo…6.9
- CVE-2026-59239Stored Cross-site Scripting (CWE-79) in the email module in …8.6
- CVE-2026-59240The vulnerability involves an Insecure Direct Object Referen…6.9
- CVE-2026-59242Apache Airflow's XCom `GET /api/v2/{...}/xcomEntries/{key}?d…
- CVE-2026-59244Apache Airflow's secrets masker did not mask `var.json` Vari…
- CVE-2026-59245In the Apache Airflow FAB auth manager, a DAG whose `dag_id`…8.1
- CVE-2026-59246Allocation of resources without limits vulnerability in elix…6.3
- CVE-2026-59247Insufficient Verification of Data Authenticity vulnerability…7.6
- CVE-2026-59248Allocation of resources without limits vulnerability in nine…8.7
- CVE-2026-59249Inconsistent interpretation of HTTP requests (HTTP response …6.3
Are you affected by CVE-2026-59243?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST