The HashiCorp Vault secrets backend in Apache Airflow’s HashiCorp provider improperly processes a user‑supplied key that contains a path separator. After a team‑scoped lookup fails, the backend falls back to an unvalidated, team‑agnostic path built from that key, allowing resolution of secrets that belong to other teams. This flaw, identified as CWE‑639, permits an actor to read secrets that were intended to be isolated by team boundaries.

Deployments of the Apache Airflow HashiCorp provider that use the Vault secrets backend in multi‑team environments are impacted. The issue exists in all releases before version 4.8.0 of apache‑airflow‑providers‑hashicorp; single‑team installations are not affected because there is no cross‑team boundary to traverse.

EPSS data indicates a probability under 1% and the CVSS score is 6.5, classifying this vulnerability as medium severity, and it is not listed in CISA KEV. The flaw can be triggered through normal DAG code executed via the Execution API Variables route, which accepts a path‑shaped key. Based on the description, it is inferred that an attacker would need access to create or modify a DAG that has privilege to specify Variable keys for their team. When exercised, the attacker can read any secret that other teams have stored in Vault, resulting in a significant confidentiality breach for multi‑team environments.