Apache Airflow Task SDK Callback deserialization can import arbitrary modules in the scheduler

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.8 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-67587: 0.61% estimated exploitation activity in the next 30 days; percentile 49.34 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 alloweddeserializationclasses allow-list, so tightening that setting does not help. A Dag author — who controls a task instance's nextkwargs through the task execution API — can therefore cause an arbitrary module to be imported inside the scheduler process, when the scheduler's awaitinginput 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.

Published by the source

12 Aug 2026, 18:31 UTC

Last modified by the source

2 Oct 2026, 23:15 UTC

Source last checked

26 Oct 2026, 13:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2qjv-p2gc-mjg2

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# Patch Next advisory brief: CVE-2026-67587

Advisory: Apache Airflow Task SDK Callback deserialization can import arbitrary modules in the scheduler
IDs: CVE-2026-67587, GHSA-2qjv-p2gc-mjg2
Record: https://patchnext.com/advisories/cve-2026-67587 (revision 1, source checked 26 Oct 2026, 13:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: apache-airflow 3.3.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI apache-airflow: affected >= 3.3.0, < 3.3.1; fixed in 3.3.1

## Suggested inspection (read-only)
- `python -m pip show apache-airflow`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on apache-airflow.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2qjv-p2gc-mjg2 (GitHub-reviewed advisory GHSA-2qjv-p2gc-mjg2 lists affected ranges: PyPI apache-airflow >=3.3.0 <3.3.1)

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