CVE-2026-48828: Apache Airflow Information Disclosure Issue

CVE-2026-48828 Overview

CVE-2026-48828 is an information disclosure vulnerability in the Bulk Variables API of Apache Airflow. The API invoked the redactor without passing the variable's key, preventing the key-based should_hide_value_for_key check from firing on JSON-decodable variable values. This check normally redacts values stored under secret-suffixed key names such as *_password, *_token, and *_secret. An authenticated user with bulk Variable read permission can retrieve plaintext values from JSON-typed Airflow Variables that would otherwise be redacted. The flaw is classified under [CWE-200] Information Exposure.

Critical Impact
Authenticated users with bulk Variable read permission can extract plaintext secrets (passwords, tokens, API keys) from JSON-typed Airflow Variables through the Bulk Variables API.

Affected Products

Apache Airflow versions prior to 3.3.0
Apache Airflow 3.2.2 and earlier 3.2.x releases (no backport provided)
Deployments storing sensitive values in JSON-typed Airflow Variables under secret-suffixed key names

Discovery Timeline

2026-07-07 - CVE-2026-48828 published to NVD
2026-07-08 - Last updated in NVD database

Technical Details for CVE-2026-48828

Vulnerability Analysis

Apache Airflow redacts sensitive Variable values using two mechanisms: a key-name heuristic and a value-content heuristic. The should_hide_value_for_key function inspects the Variable key for secret-indicative suffixes such as _password, _token, _secret, and _key. When triggered, the redactor replaces the value with *** before returning it through the API.

The Bulk Variables API endpoint invoked the redactor without forwarding the Variable's key. As a result, the key-based check had no key to evaluate and never triggered. For scalar string values, other redactor heuristics may still apply. For JSON-decodable values, however, the missing key context allowed the raw structured payload to pass through unredacted.

Root Cause

The root cause is an incomplete parameter contract between the Bulk Variables API and the internal redaction routine. The redactor requires the Variable key to perform key-name pattern matching, but the bulk endpoint omitted this argument in its call path. See the fix in Apache Airflow PR #67495.

Attack Vector

Exploitation requires an authenticated session with bulk Variable read permission on the Airflow UI or REST API. The attacker issues a bulk read request against Variables whose keys carry secret-indicative suffixes and whose values are JSON-decodable. The API responds with plaintext contents that would be redacted through single-Variable retrieval paths. No user interaction, elevated privileges, or network complexity are required beyond initial authentication.

Detection Methods for CVE-2026-48828

Indicators of Compromise

Bulk Variable GET requests from accounts that do not typically consume Variables in bulk
Access log entries hitting the bulk Variables REST endpoint targeting Variables with *_password, *_token, *_secret, or *_key naming
Response payloads containing structured JSON values under secret-suffixed keys, indicating redaction did not fire
Anomalous export volume from service accounts or CI/CD tokens with Variable read scope

Detection Strategies

Audit Airflow webserver and API access logs for requests to bulk Variable endpoints, correlating user, timestamp, and requested key patterns
Enable Airflow audit logging and forward events to a centralized SIEM or data lake for retention and correlation
Baseline normal Variable read behavior per user and alert on deviations in request rate or key selection

Monitoring Recommendations

Ingest Airflow API and webserver logs into a centralized analytics platform such as Singularity Data Lake for OCSF-normalized retention and query
Alert on any bulk Variable read that returns values under keys matching secret-suffix regex patterns
Track authentication events and role changes granting bulk Variable read permission
Review Variables inventory quarterly and migrate secrets out of Airflow Variables into a dedicated secrets backend

How to Mitigate CVE-2026-48828

Immediate Actions Required

Upgrade Apache Airflow to version 3.3.0 or later, which contains the fix merged after 3.2.2
Rotate all secrets previously stored in JSON-typed Variables with secret-suffixed key names, since prior reads may have exposed them
Review and reduce accounts holding bulk Variable read permission to the minimum required set
Migrate sensitive values from Airflow Variables to a dedicated secrets backend such as HashiCorp Vault, AWS Secrets Manager, or GCP Secret Manager

Patch Information

The fix landed on the main branch after release 3.2.2 and ships in apache-airflow 3.3.0. No 3.2.x backport was provided. Operators on the 3.2.x line must upgrade to 3.3.0 to remediate. Technical details are available in the Apache Airflow GitHub Pull Request and the Apache mailing list announcement.

Workarounds

Configure Airflow to source secrets from an external secrets backend rather than storing them in Variables
Convert JSON-typed Variables that hold secrets into individual scalar Variables so per-key redaction paths apply
Restrict the Variables.can_read and bulk API permissions to a small, audited group of operators until the upgrade is complete
Place the Airflow API behind a reverse proxy that authenticates and logs all Variable-related endpoints

bash

# Upgrade Apache Airflow to the fixed release
pip install --upgrade "apache-airflow==3.3.0"

# Verify installed version
airflow version

# Optional: configure an external secrets backend in airflow.cfg
# [secrets]
# backend = airflow.providers.hashicorp.secrets.vault.VaultBackend
# backend_kwargs = {"url": "https://vault.example.com", "mount_point": "airflow"}