{"id":"CVE-2026-33264","aliases":["BIT-airflow-2026-33264","GHSA-2943-9672-r45w","PYSEC-2026-2082"],"url":"https://o3.security/vulnerability/CVE-2026-33264","summary":"Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize()","details":"A bug in `BaseSerialization.deserialize()` allowed unrestricted `import_string()` of attacker-controlled class paths when the Scheduler / API Server loaded a serialized DAG: a DAG author could embed a malicious trigger into a DAG to gain remote code execution on the API Server / Scheduler process, crossing the Airflow security boundary that DAG-author code must never execute in those processes. Users are advised to upgrade to `apache-airflow` 3.3.0 or later. As a defense-in-depth mitigation, deployments where DAG-author trust is limited can restrict the `[core] allowed_deserialization_classes` config to a narrow allowlist.","published":"2026-07-07T09:20:18.518Z","modified":"2026-09-04T19:40:19.933602916Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"apache-airflow","fixedVersion":"3.3.0"}],"fix":{"url":"https://github.com/apache/airflow/pull/66002","label":"apache/airflow#66002"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/07/07/1"},{"type":"WEB","url":"https://pypi.python.org"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33264.json"},{"type":"ADVISORY","url":"https://lists.apache.org/thread/otvdw8qt2y7xy2n5nq9xby9ky4rf5ltj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33264"},{"type":"FIX","url":"https://github.com/apache/airflow/pull/66002"},{"type":"FIX","url":"https://github.com/apache/airflow/pull/68528"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-04T19:40:19.933602916Z"}}