CVE-2026-81930: Apache Airflow Snowflake provider: Unvalidated account field redirects SQL API bearer token off-domain

Apache Airflow’s Snowflake provider, before apache-airflow-providers-snowflake 6.18.0, interpolated the connection’s account and region fields into request URLs without validating them. The SQL API URL is built as https://{account}.snowflakecomputing.com/api/v2/statements, so an account value containing "/", "?", or "#" turns the intended Snowflake host into a path, query, or fragment and sends the request, including an Authorization Bearer JWT or configured OAuth or programmatic access token, to a host the editor chooses; the same unvalidated value was used for the OAuth token-request URL and the Cortex Agent base URL. A user who can edit the Snowflake connection but cannot read its secrets can capture a valid token and replay it against the real Snowflake account, without authoring a Dag and without access to a private_key_file that stays on the worker. Deployments are affected only where Snowflake connections are editable by users who are not trusted with those credentials. No public proof of concept is known, CISA’s KEV catalog does not list it, and there is no report of in-the-wild exploitation; CVSS has not yet been scored.