CVE-2026-40861: Apache Airflow: Arbitrary File Read via Log Symlink following in FileTaskHandler
This Apache advisory covers CVE-2026-40861 in Apache Airflow.
- CVE-2026-40861
Key facts
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N· base score 6.5, scored by CISA-ADPAttack vector: network. Attack complexity: low. Privileges required: low. User interaction: none. Scope: unchanged. Confidentiality impact: high. Integrity impact: none. Availability impact: none.- Weakness
- CWE-59: Improper Link Resolution Before File Access ('Link Following')
- CISA SSVC
- Exploitation: none observed. Automatable: no. Technical impact: partial. CISA, .
- CISA KEV
- Not listed (catalogue checked )
- Affected
- Apache Airflow before 3.0.0; Apache Airflow 3.0.0 before 3.2.2
- Fixed in
- 3.0.0, 3.2.2
- Source published
- Source revised
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
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.
Text from the source record.
- Apache Airflow before 3.0.0
- Apache Airflow 3.0.0 before 3.2.2
Official advisory · medium-confidence parse· fetched ·verify at source
How to fix CVE-2026-40861
Upgrade to a fixed release named by Apache:
- 3.0.0
- 3.2.2
Vendor guidance
- 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.
Support dates for the fixed release lines
- Apache Airflow 3.0: support ended
- Apache Airflow 3.2: support ended
More Apache Software Foundation advisories
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Apache Software Foundation advisories, June 2026All Apache Software Foundation advisories
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