Apache Airflow allows code execution through unsafe serialized DAG deserialization

Exploitation

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

CVSS

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

EPSS

• CVE-2026-33264: 1.65% estimated exploitation activity in the next 30 days; percentile 76.52 (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.

A bug in BaseSerialization.deserialize() allowed unrestricted importstring() of attacker-controlled class paths when the Scheduler / API Server loaded a serialized DAG: a DAG author could embed a malicious trigger into a DAG to gain remote code execution on the API Server / Scheduler process, crossing the Airflow security boundary that DAG-author code must never execute in those processes. Users are advised to upgrade to apache-airflow 3.3.0 or later. As a defense-in-depth mitigation, deployments where DAG-author trust is limited can restrict the [core] alloweddeserializationclasses config to a narrow allowlist.

Published by the source

7 Jul 2026, 12:31 UTC

Last modified by the source

4 Sep 2026, 19:40 UTC

Source last checked

26 Oct 2026, 13:51 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-2943-9672-r45w

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-2943-9672-r45w

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-2943-9672-r45w

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# Patch Next advisory brief: CVE-2026-33264

Advisory: Apache Airflow allows code execution through unsafe serialized DAG deserialization
IDs: CVE-2026-33264, GHSA-2943-9672-r45w
Record: https://patchnext.com/advisories/cve-2026-33264 (revision 3, source checked 26 Oct 2026, 13:51 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: apache-airflow 3.3.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI apache-airflow: affected < 3.3.0; fixed in 3.3.0

## 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-2943-9672-r45w (GitHub-reviewed advisory GHSA-2943-9672-r45w lists affected ranges: PyPI apache-airflow >=0 <3.3.0)
- Verified: https://osv.dev/vulnerability/GHSA-2943-9672-r45w (OSV record GHSA-2943-9672-r45w lists affected ranges: PyPI apache-airflow >=0 <3.3.0 (fixed))

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