What’s Vulnerable › Vulnerabilities

CVE-2026-33264: Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize()

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-07 · updated 2026-10-25
• Weakness: CWE-502

Description

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.

Affected products

• Apache Airflow: before 3.3.0 — fixed in 3.3.0

How to fix

Upgrade to a fixed version: Apache Airflow 3.3.0. Check the vendor advisory for mitigations.

References

• https://github.com/apache/airflow/pull/66002
• https://github.com/apache/airflow/pull/68528
• https://lists.apache.org/thread/otvdw8qt2y7xy2n5nq9xby9ky4rf5ltj
• http://www.openwall.com/lists/oss-security/2026/07/07/1

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