---
title: "CVE-2026-33264: Apache Airflow allows code execution through unsafe serialized DAG deserialization"
url: https://erroneo.us/security/cve/CVE-2026-33264/
description: "CVE-2026-33264 (apache-airflow (PyPI)): A bug in BaseSerialization.deserialize() allowed unrestricted importstring() of attacker-controlled class paths when…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-07-07
date_modified: 2026-09-04
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-33264"
kev: false
cvss: 9.8
epss: 0.01649
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-33264: Apache Airflow allows code execution through unsafe serialized DAG deserialization

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 1.6% , percentile 76: FIRST’s model estimates a 1.6% chance of exploitation activity in the next 30 days, higher than 76% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes apache-airflow (PyPI) < 3.3.0, fixed in 3.3.0 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- PyPI `apache-airflow` < 3.3.0 → fixed: 3.3.0

## Affected products (CVE record)

- Apache Software Foundation Apache Airflow: < 3.3.0

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.65% probability of exploitation activity in the next 30 days; percentile 76.

## Sources

- [github.com](https://github.com/apache/airflow/pull/66002)
- [github.com](https://github.com/apache/airflow/pull/68528)
- [lists.apache.org](https://lists.apache.org/thread/otvdw8qt2y7xy2n5nq9xby9ky4rf5ltj)
- [GitHub Advisory GHSA-2943-9672-r45w](https://github.com/advisories/GHSA-2943-9672-r45w)
- [CVE.org record CVE-2026-33264](https://www.cve.org/CVERecord?id=CVE-2026-33264)
- [NVD entry CVE-2026-33264](https://nvd.nist.gov/vuln/detail/CVE-2026-33264)
- [openwall.com](http://www.openwall.com/lists/oss-security/2026/07/07/1)
- [github.com](https://github.com/apache/airflow/commit/69b6c54ef17b048ebb0e9a656d0d9e1c99480d6b)
- [github.com](https://github.com/apache/airflow/commit/7e9bdb245e09373d91fcb7bda575ad4be63aa28d)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-2082.yaml)

---
Source page: https://erroneo.us/security/cve/CVE-2026-33264/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt