{"id":"PYSEC-2026-3708","details":"Apache Airflow's Task SDK rebuilt a `Callback` object from serialized data by re-running its constructor, which imports the module named by the stored callback path. Because `SyncCallback` is itself an Airflow class it passes the default `allowed_deserialization_classes` allow-list, so tightening that setting does not help. A Dag author — who controls a task instance's `next_kwargs` through the task execution API — can therefore cause an arbitrary module to be imported inside the scheduler process, when the scheduler's `awaiting_input` timeout sweep deserializes that value. No non-default configuration is required; the sweep runs unconditionally. Versions before 3.3.0 are not affected: the class existed, but the scheduler sweep that reaches it did not. This is a separate code path from CVE-2026-58076 and CVE-2026-67260, which cover different gadgets reaching deserialization — applying either of those fixes does not address this one. Users are advised to upgrade to apache-airflow 3.3.1 or later.","aliases":["BIT-airflow-2026-67587","CVE-2026-67587"],"modified":"2026-08-19T13:55:45.316551280Z","published":"2026-08-12T16:17:15.090Z","references":[{"type":"WEB","url":"https://www.cve.org/CVERecord?id=CVE-2026-58076"},{"type":"WEB","url":"https://www.cve.org/CVERecord?id=CVE-2026-67260"},{"type":"ADVISORY","url":"https://lists.apache.org/thread/o00ww4n69qojvsckb464dtwd2nhzy6t0"},{"type":"FIX","url":"https://github.com/apache/airflow/pull/70704"}],"affected":[{"package":{"name":"apache-airflow","ecosystem":"PyPI","purl":"pkg:pypi/apache-airflow"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.3.0"},{"fixed":"3.3.1"}]}],"versions":["3.3.0","3.3.1rc1","3.3.1rc2"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/apache-airflow/PYSEC-2026-3708.yaml"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}