CVE-2026-25219: Apache Airflow Information Disclosure Flaw

CVE-2026-25219 Overview

CVE-2026-25219 is an Information Disclosure vulnerability in Apache Airflow where the access_key and connection_string connection properties were not marked as sensitive names in the secrets masker. This oversight allows users with read permission to view sensitive credential values in the Connection UI and in application logs when connections are accidentally logged.

The vulnerability primarily impacts Azure Service Bus connections that utilize these properties to store sensitive authentication values. Other connection providers may also be affected if they use the same fields to store sensitive data.

Critical Impact

Sensitive credentials including access keys and connection strings may be exposed to unauthorized users with read permissions, potentially leading to unauthorized access to connected services like Azure Service Bus.

Affected Products

• Apache Airflow versions prior to 3.1.8
• Azure Service Bus connections using access_key or connection_string properties
• Other connection providers storing sensitive data in these fields

Discovery Timeline

• April 15, 2026 - CVE-2026-25219 published to NVD
• April 15, 2026 - Last updated in NVD database

Technical Details for CVE-2026-25219

Vulnerability Analysis

This vulnerability stems from an incomplete implementation of the secrets masking functionality in Apache Airflow. The secrets masker is designed to redact sensitive information from logs and UI displays to prevent credential exposure. However, the access_key and connection_string fields were not included in the list of sensitive property names that should be masked.

When a connection is displayed in the Airflow Connection UI, users with read permissions can view the unmasked values of these properties. Additionally, if connections are inadvertently logged during debugging or error conditions, the sensitive values appear in plain text within the log files.

The vulnerability is classified as CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), reflecting the unauthorized disclosure of credential data to users who should not have access to the actual values.

Root Cause

The root cause of this vulnerability is the omission of access_key and connection_string from the secrets masker's list of sensitive field names. The masking mechanism relies on a predefined list of property names to identify which values should be redacted. Without explicit inclusion in this list, these fields were treated as non-sensitive data and displayed in cleartext.

Attack Vector

The attack vector for this vulnerability requires network access and authenticated access with read permissions to the Airflow instance. An attacker with legitimate read-only access to the Airflow Connection UI can view sensitive credential values that should be masked. The exploitation path includes:

1. Attacker obtains read-level access to the Apache Airflow web interface
2. Attacker navigates to the Connections section of the UI
3. Attacker views connection details for Azure Service Bus or other affected connections
4. Sensitive access_key and connection_string values are displayed in plain text
5. Attacker can use exposed credentials to access connected services

Additionally, if Airflow logs are accessible to the attacker (either through the UI or log management systems), any accidentally logged connection data would expose these sensitive values.

Detection Methods for CVE-2026-25219

Indicators of Compromise

• Unexpected access to Connection details pages by users with read-only permissions
• Audit logs showing repeated queries to connection configuration endpoints
• Log entries containing unmasked access_key or connection_string values
• Anomalous authentication attempts to Azure Service Bus or other connected services using exposed credentials

Detection Strategies

• Review Airflow audit logs for unusual access patterns to Connection UI pages
• Search existing log files for occurrences of access_key or connection_string that may contain exposed credentials
• Monitor Azure Service Bus and other connected services for authentication attempts from unexpected sources
• Implement log scanning to detect potential credential leakage in historical logs

Monitoring Recommendations

• Enable detailed access logging for the Airflow web interface
• Configure alerts for bulk access to connection configuration data
• Implement monitoring on connected services for unusual authentication patterns
• Consider rotating credentials that may have been exposed prior to patching

How to Mitigate CVE-2026-25219

Immediate Actions Required

• Upgrade Apache Airflow to version 3.1.8 or later immediately
• Rotate all access_key and connection_string credentials stored in affected connections
• Review access logs to identify any potential credential exposure
• Audit user permissions to ensure read access is appropriately restricted

Patch Information

Apache has released patches addressing this vulnerability in the following pull requests:

• GitHub Pull Request #61580 - Primary fix for secrets masker
• GitHub Pull Request #61582 - Additional hardening

The fix adds access_key and connection_string to the list of sensitive field names in the secrets masker, ensuring these values are properly redacted in the UI and logs.

Additional information is available in the Apache Mailing List Thread and the Openwall OSS-Security Post.

Workarounds

• Restrict read access to Airflow Connections to only essential personnel until patching is complete
• Review and purge logs that may contain exposed credential values
• Consider using alternative authentication methods that do not store sensitive values in these fields
• Implement network segmentation to limit access to the Airflow web interface

# Upgrade Apache Airflow to patched version
pip install apache-airflow==3.1.8

# Verify the installed version
airflow version

# After upgrading, rotate affected credentials in your connections
# Access the Airflow UI and update Azure Service Bus connections with new credentials