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Fencer Vulns
critical 9.8

CVE-2026-33264 json

Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize()

published 2026-07-07 4 mo ago modified 2026-11-03 6 d ago also BIT-airflow-2026-33264 , EUVD-2026-42030 , GHSA-2943-9672-r45w , PYSEC-2026-2082

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

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` 3.3.0 or later. As a defense-in-depth mitigation, deployments where DAG-author trust is limited can restrict the `[core] allowed_deserialization_classes` config to a narrow allowlist.

Patch / fix

  • pypi apache-airflow 3.3.0
  • bitnami airflow 3.3.0
  • Apache Software Foundation Apache Airflow 3.0.0, 3.3.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
4 mo ago

Exploit prediction

1.65% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
OSV 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi apache-airflow
<3.3.0
3.3.0
bitnami airflow
<3.3.0
3.3.0

Affected products

  • Apache Software Foundation Apache Airflow

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.