Apache Airflow <3.2.2: Log Path Traversal via FileTaskHandler
CVE-2026-40861 Published on June 1, 2026

Apache Airflow: Arbitrary File Read via Log Symlink following in FileTaskHandler
A Dag author could either (a) create a symlink under their task's log directory pointing to an arbitrary file readable by the API server process (read-path attack e.g. `/etc/passwd` or `airflow.cfg`) or (b) supply a `task_id` containing `..` sequences accepted by the Task SDK's `KEY_REGEX` (write-path attack), and in both cases the FileTaskHandler resolves the log path outside the configured `base_log_folder`, leaking or overwriting arbitrary files. Only affects deployments where the worker log folder is shared with the API server. Users are advised to upgrade to `apache-airflow` 3.2.2 or later. As a defense-in-depth mitigation, deploy the worker and API server with separate log volumes so that worker-controlled paths cannot reach the API server's filesystem.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-40861 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
NONE
Availability Impact:
NONE

Weakness Type

What is an insecure temporary file Vulnerability?

The software attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

CVE-2026-40861 has been classified to as an insecure temporary file vulnerability or weakness.


Products Associated with CVE-2026-40861

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Affected Versions

Apache Software Foundation Apache Airflow:

Exploit Probability

EPSS
0.67%
Percentile
46.90%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.