{"id":"CVE-2026-40861","aliases":["GHSA-89cj-xrpx-j79m","BIT-airflow-2026-40861","PYSEC-2026-181"],"title":"Apache Airflow has a Link Following issue","summary":"Apache Airflow has a Link Following issue","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","vendor":"apache-airflow","product":"apache-airflow","ecosystem":"pip","affected":["apache-airflow < 3.2.2"],"patched":["apache-airflow 3.2.2"],"published":"2026-06-01","updated":"2026-07-09","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-89cj-xrpx-j79m","references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40861"},{"url":"https://github.com/apache/airflow/pull/65325"},{"url":"https://github.com/apache/airflow"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-181.yaml"},{"url":"https://lists.apache.org/thread/823334db2559xjlwt59gpzjz47thnscl"},{"url":"http://www.openwall.com/lists/oss-security/2026/05/31/1"}],"tags":["osv","pip"],"epss":0.00691,"epssPercentile":0.51417,"ingestedAt":"2026-07-10T13:49:10.618Z","slug":"CVE-2026-40861","body":"## Overview\n\nA 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.\n\n## Affected packages\n\n- `apache-airflow < 3.2.2`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `apache-airflow 3.2.2`","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}