Vulnerability · Published Jul 7, 2026 · Assigned by apache
CVE-2026-33264Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize()
Critical 9.8
In plain English
A critical-severity unsafe deserialization in Apache Airflow from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.6% (higher than 77% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | apache-airflow | 3.3.0 | GHSA-2943-9672-r45w |
| PyPI | apache-airflow | 3.3.0 | PYSEC-2026-2082 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache Airflow | 0 – before 3.0.0 |
| Apache Software Foundation | Apache Airflow | 3.0.0 – before 3.3.0 |
Weakness: CWE-502 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H