CVE-2026-49297: Apache Airflow Google provider: Path traversal via GCS object names → local/SFTP filesystem (GCSToSFTPOperator + GCSTimeSpanFileTransformOperator)

[Shahar Epstein <shahar () apache org>]

Severity: moderate 

Affected versions:

- Apache Airflow Google provider (apache-airflow-providers-google) before 22.2.1

Description:

Apache Airflow's Google provider operators `GCSToSFTPOperator` and `GCSTimeSpanFileTransformOperator` joined GCS object 
names returned by the bucket listing API directly to a destination filesystem path without normalisation or containment 
check. A user with write access to the source GCS bucket (typically a different trust principal than the DAG author — 
partner uploads, ingest-only service accounts, public-data buckets) could create an object whose name contains `..` 
segments and cause the DAG run to write the downloaded blob outside the configured destination (the SFTP 
`destination_path` for `GCSToSFTPOperator`; the worker-local temp directory for `GCSTimeSpanFileTransformOperator`), 
enabling overwrite of arbitrary files on the SFTP server or the worker host. Affects deployments that ingest from 
buckets writable by less-trusted principals. Users are advised to upgrade to `apache-airflow-providers-google` 22.2.1 
or later.

Credit:

anonymous (finder)
Jarek Potiuk (remediation developer)

References:

https://github.com/apache/airflow/pull/67667
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-49297