CVE-2026-97636 in Airflow HashiCorp Provider
Summary
by MITRE • 09/25/2026
Apache Airflow HashiCorp provider: the HashiCorp Vault secrets backend's team-scope guard can be bypassed with a user-controlled key. In a multi-team deployment, a Dag author scoped to one team can supply a Variable key containing a path separator that causes the backend to resolve a secret belonging to a different team, because after the team-scoped lookup misses the backend falls back to a team-agnostic path concatenated from the unvalidated key. The Execution API Variables route accepts a path-shaped key, so this is reachable from ordinary Dag code.
Affects multi-team deployments using the HashiCorp Vault secrets backend. Single-team deployments are not affected, as there is no cross-team boundary to cross. This is the same class as CVE-2026-86465, CVE-2026-68870, CVE-2026-68871 and CVE-2026-68872 in the Akeyless, Azure Key Vault, Yandex Lockbox and Amazon secrets backends.
Users of apache-airflow-providers-hashicorp are recommended to upgrade to version 4.8.0 or later, which fixes the issue.
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Analysis
by VulDB Data Team • 09/25/2026
The Apache Airflow HashiCorp provider contains a critical security vulnerability within its integration with the HashiCorp Vault secrets backend that allows for unauthorized access to sensitive data across team boundaries in multi-tenant environments. This flaw specifically affects deployments where multiple teams share an Airflow instance but are intended to operate under strict isolation policies enforced by the secrets manager. The core issue lies in how the system handles Variable keys provided by DAG authors when retrieving secrets from Vault. In a properly secured configuration, each user or team is scoped to a specific path within the HashiCorp Vault hierarchy, ensuring that they can only access resources explicitly assigned to their domain. However, the current implementation fails to adequately sanitize input variables before using them as lookup paths, creating an opportunity for path traversal attacks.
The technical mechanism of this vulnerability involves the fallback behavior of the secrets backend when a direct team-scoped lookup fails. When a DAG author supplies a Variable key that contains a path separator character, such as a forward slash, the system attempts to resolve the secret using the user's scoped prefix first. If this initial attempt does not yield a result because the specific key is not present in the authorized scope, the backend falls back to an alternative resolution strategy. This fallback mechanism concatenates the unvalidated user-controlled key directly onto a base path without checking for directory traversal sequences or ensuring that the resulting path remains within the permitted boundaries of the current team's namespace. Consequently, by carefully crafting a Variable key with embedded slashes and relative paths like dot-dot-slash, an attacker can navigate up the Vault hierarchy to access secrets belonging to other teams or even global administrative credentials stored in higher-level directories.
This vulnerability is particularly dangerous because it leverages standard operational workflows within Apache Airflow. The Execution API Variables route accepts path-shaped keys as part of its normal function for managing dynamic configuration values in DAGs. Since any user with the ability to create and execute DAGs can define these variables, the attack surface is broad and easily accessible from ordinary Dag code without requiring elevated privileges or external network access beyond what is already granted to developers working on data pipelines. The impact extends beyond simple information disclosure; if an attacker gains access to high-privilege secrets such as database connection strings for production systems or API keys with administrative rights, they can potentially compromise the integrity and availability of downstream services connected through Airflow. This represents a significant breach of multi-tenancy isolation guarantees that organizations rely on when sharing infrastructure resources among different departments or external partners.
From a classification perspective, this vulnerability aligns closely with CWE-20 Improper Input Validation, as the system fails to verify that user-supplied input conforms to expected constraints regarding path structure and scope boundaries. It also maps directly to MITRE ATT&CK technique T1537, which involves Communication Through Distributed Component Interface, specifically in the context of abusing internal API endpoints like the Variables route to exfiltrate data from protected storage systems. The flaw is part of a broader class of issues affecting various cloud secrets backends integrated with Airflow, including Akeyless, Azure Key Vault, Yandex Lockbox, and Amazon Secrets Manager, indicating a systemic pattern in how these integrations handle path resolution logic during fallback scenarios rather than an isolated implementation error unique to HashiCorp.
To mitigate this risk, organizations using Apache Airflow must immediately upgrade the apache-airflow-providers-hashicorp package to version 4.8.0 or later, where the developers have implemented stricter validation rules for Variable keys and corrected the path resolution logic to prevent traversal outside of authorized scopes. In addition to upgrading software components, security teams should review existing DAGs for any usage patterns that rely on dynamic variable names containing slashes or relative paths, as these may be susceptible to exploitation even after patching if custom code overrides default behaviors. Implementing additional network-level controls such as Vault policies that restrict read access based on IP ranges or service accounts can provide defense-in-depth measures while the migration to patched versions is completed. Regular audits of secrets management configurations and enforcement of least-privilege principles for DAG authors will further reduce the likelihood of successful exploitation in future deployments.