---
id: CVE-2026-67587
title: >-
  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
summary: >-
  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…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: apache
product: airflow
affected:
  - 'airflow >= 3.3.0, < 3.3.1'
patched:
  - airflow 3.3.1
published: '2026-08-12'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:17:41.107'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67587'
references:
  - url: 'https://github.com/apache/airflow/pull/70704'
    label: security@apache.org
  - url: 'https://lists.apache.org/thread/o00ww4n69qojvsckb464dtwd2nhzy6t0'
    label: security@apache.org
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-58076'
    label: security@apache.org
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-67260'
    label: security@apache.org
tags:
  - nvd
  - cve.org
  - osv
  - pip
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-13T12:17:23.923988Z'
epss: 0.01165
epssPercentile: 0.659
aliases:
  - PYSEC-2026-3708
  - BIT-airflow-2026-67587
ecosystem: pip
ingestedAt: '2026-08-19T19:22:21.380Z'
---

## Overview

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.

## Affected

- `airflow >= 3.3.0, < 3.3.1`

## Remediation

Upgrade past the affected range:

- `airflow 3.3.1`

## Package advisory (CVE-2026-67587)

Affected packages:

- `apache-airflow >= 3.3.0, < 3.3.1`

Patched in:

- `apache-airflow 3.3.1`

Source: https://osv.dev/vulnerability/PYSEC-2026-3708