CVE-2021-26559Network attack vector

Sensitive configuration disclosure via overprivileged default roles

Published Feb 17, 2021 · Updated Feb 13, 2025

Improper access control in Apache Airflow 2.0.0 allows remote authenticated users to read sensitive configuration through the stable API. The default Viewer and User roles retain Configurations.can_read, so GET /api/v1/config returns data even when expose_config is false. Viewer- or User-role access is required; disclosed secrets can support privilege escalation, while direct data modification is not reported.

CVSS severity7.1
High
EPSS probability2.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Apache Airflow 2.0.0 allows remote authenticated users to read sensitive configuration through the stable API. The default Viewer and User roles retain Configurations.can_read, so GET /api/v1/config returns data even when expose_config is false. Viewer- or User-role access is required; disclosed secrets can support privilege escalation, while direct data modification is not reported.

The record

CVE
CVE-2021-26559
Published
Feb 17, 2021
Updated
Feb 13, 2025
Vendor
The Apache Software Foundation
Product
Apache Airflow
Classifications
CWE-269, CWE-284, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Apache Airflow 2.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache Airflowversion=Apache Airflow 2.0.0

Published CVSS scores

7.1GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
6.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
CWE-284Improper Access Control
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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