CVE-2026-67587
Because `SyncCallback` is itself an Airflow class it passes the default `allowed_deserialization_classes` allow-list, so tightening that setting does not help.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.61% probability · 47th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-502
- Affected
- apache/airflow
- Source
- security@apache.org
References
- https://github.com/apache/airflow/pull/70704Issue Tracking, Patch
- https://lists.apache.org/thread/o00ww4n69qojvsckb464dtwd2nhzy6t0Mailing List, Vendor Advisory
- https://www.cve.org/CVERecord?id=CVE-2026-58076Not Applicable
- https://www.cve.org/CVERecord?id=CVE-2026-67260Not Applicable
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.