CVE-2021-26559

Name: CVE-2021-26559
Creator: NVD / NIST
Published: 2021-02-17T15:15:13.5+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 2.80%

Last modified Jun 17, 2026

CVE-2021-26559 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Improper Access Control on Configurations Endpoint for the Stable API of Apache Airflow allows users with Viewer or User role to get Airflow Configurations including sensitive information even when `[webserver] expose_config` is set to `False` in `airflow.cfg`. This allowed a privilege escalation attack. EPSS estimates a 2.80% chance of exploitation in the next 30 days.

Description

Improper Access Control on Configurations Endpoint for the Stable API of Apache Airflow allows users with Viewer or User role to get Airflow Configurations including sensitive information even when `[webserver] expose_config` is set to `False` in `airflow.cfg`. This allowed a privilege escalation attack. This issue affects Apache Airflow 2.0.0.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

2.80%

84.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-284

Affected Software

Vendor	Product	Versions
Apache	Airflow	2.0.0

References

http://www.openwall.com/lists/oss-security/2021/02/17/1Mailing List, Third Party Advisory
https://lists.apache.org/thread.html/r3b3787700279ec361308cbefb7c2cce2acb26891a12ce864e4a13c8d%40%3Cusers.airflow.apache.org%3EMailing List, Vendor Advisory
https://lists.apache.org/thread.html/rd142565996d7ee847b9c14b8a9921dcf80bc6bc160e3d9dca6dfc2f8%40%3Cannounce.apache.org%3E
http://www.openwall.com/lists/oss-security/2021/02/17/1Mailing List, Third Party Advisory
https://lists.apache.org/thread.html/r3b3787700279ec361308cbefb7c2cce2acb26891a12ce864e4a13c8d%40%3Cusers.airflow.apache.org%3EMailing List, Vendor Advisory
https://lists.apache.org/thread.html/rd142565996d7ee847b9c14b8a9921dcf80bc6bc160e3d9dca6dfc2f8%40%3Cannounce.apache.org%3E

Timeline

Published: Feb 17, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-26559?

How severe is CVE-2021-26559?

CVE-2021-26559 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 2.80% probability of exploitation in the next 30 days.

How do I fix CVE-2021-26559?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-26559?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST