CVE-2026-33264: A bug in `BaseSerialization.deserialize()` allowed unrestricted `import_string()` of attacker-controlled class

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-33264 is a critical-severity flaw (CVSS 9.8) affecting airflow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A bug in `BaseSerialization.deserialize()` allowed unrestricted `import_string()` 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

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.6% (top 24%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-07-07
Last modified	2026-10-25

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-07 10:16 UTCPublished CVE record published
2026-10-25 20:10 UTCUpdated Record last modified

apache airflow UPGRADE

Affected: < 3.3.0

Fixed in: 3.3.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy airflow || rpm -q airflow || airflow --version

2. UPGRADE to 3.3.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade airflow

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade airflow

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Python (pip) · apache-airflow · FIXED · 3.3.0 · vulnerable: < 3.3.0 · source

pip install --upgrade "apache-airflow>=3.3.0" pip show apache-airflow

Fedora 46 · python-apprise · FIXED · 2.1.0-1.fc46 · FEDORA-2026-ef67a72c5d · source

sudo dnf upgrade --advisory=FEDORA-2026-ef67a72c5d

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33264?

airflow: upgrade to 3.3.0. Exact commands for each OS are on this page.

Is CVE-2026-33264 being exploited?

CVE-2026-33264 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33264 affect?

CVE-2026-33264 affects airflow. Severity is critical (CVSS 9.8). A bug in `BaseSerialization.deserialize()` allowed unrestricted `import_string()` 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 re

How urgent is CVE-2026-33264?

Priority 66/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Apache Airflow vulnerabilities

Related CVEs

CVE-2026-48828 MEDIUM 6.5 UPGRADE The Bulk Variables API in Apache Airflow called the redactor without passing the variable's key, so the key-ba
CVE-2026-48892 MEDIUM 6.5 UPGRADE The Config API in Apache Airflow surfaced per-key secrets-backend overrides (environment variables like `AIRFL
CVE-2026-49487 MEDIUM 6.5 UPGRADE In Apache Airflow before 3.3.0, the REST API task-instance detail and list endpoints returned a deferred task'
CVE-2026-49296 MEDIUM 6.5 UPGRADE Before apache-airflow 3.3.0, a user authorized to read one Dag could disclose the source of other Dags co-loca
CVE-2026-48891 MEDIUM 4.3 UPGRADE A bug in Apache Airflow's `/ui/dependencies` scheduling graph endpoint applied the caller's readable-Dag filte

References

← Back to latest CVEs