Airflow lets tasks read HITL data (CVE-2026-30911)

Overview

A significant authorization vulnerability has been identified in Apache Airflow, a popular platform for orchestrating complex workflows and data pipelines. Tracked as CVE-2026-30911, this security flaw affects versions 3.1.0 through 3.1.7. It allows an authenticated task instance within the system to improperly access and manipulate the Human-in-the-Loop (HITL) workflows of other, unrelated task instances.

Vulnerability Details

In simple terms, this is a permissions failure in Airflow’s Execution API. The Human-in-the-Loop feature is designed to pause a workflow and require manual human approval or rejection at specific steps. This vulnerability breaks the intended isolation between different workflows. Any task running in Airflow can exploit this flaw to read the details of, approve, or reject the HITL pauses belonging to any other task. This occurs without requiring any special privileges beyond normal task authentication.

Impact and Risks

This vulnerability carries a high severity rating with a CVSS score of 8.1. The primary impacts are:

• Unauthorized Data Access: Sensitive information contained within a paused workflow’s context can be read by unauthorized tasks.
• Process Manipulation: An attacker or a compromised task can arbitrarily approve or reject pending HITL steps. This can lead to unauthorized progression of a workflow or the wrongful rejection of a legitimate process, causing operational disruption, data corruption, or compliance violations.
• Breach of Integrity: It undermines the core security model of workflow orchestration, where tasks should be isolated and only interact as defined by the DAG (Directed Acyclic Graph).

For organizations handling sensitive data, this could facilitate a significant security incident. Staying informed about such vulnerabilities is crucial; you can follow related cybersecurity developments at security news.

Remediation and Mitigation

The Apache Airflow project has released a fix. The only complete solution is to upgrade your Airflow installation.

1. Immediate Action: Upgrade Apache Airflow to version 3.1.8 or later. This version contains the necessary authorization checks to resolve the vulnerability.
2. Verification: After upgrading, verify that the HITL endpoints now correctly enforce task instance isolation. Review your workflow logs for any suspicious activity that may have occurred prior to patching.
3. Temporary Mitigation (if upgrade is delayed): While not a substitute for patching, you can review and restrict network access to your Airflow instance to only trusted sources. Closely monitor all HITL interactions for anomalous behavior. Be aware that the vulnerability remains exploitable by any authenticated task within the system.

Proactively addressing such flaws is key to preventing data breaches. Historical incidents often stem from unpatched vulnerabilities, and you can review past events in our breach reports. System administrators should prioritize this update to maintain the security and reliability of their data pipelines.