IBM Langflow OSS 1.0.0 through 1.8.4 contain multiple broken access control vulnerabilities (CWE-639) in their file handling API. Specifically, the /api/v1/files/images/{flow_id}/{file_name} endpoint lacks authentication and authorization checks, allowing unauthenticated remote attackers to retrieve image files by specifying valid flow_id and file_name values. Additionally, the /api/v1/files/download/{flow_id}/{file_name} endpoint requires authentication but fails to validate that the authenticated user owns the requested file, resulting in an authorization bypass (IDOR). Successful exploitation can disclose sensitive data stored in private flows and compromise tenant isolation in multi-user deployments.

Unauthorized remote attackers can retrieve image files without authentication, and authenticated users can access files belonging to other users. This leads to unauthorized disclosure of sensitive data and breaks tenant isolation, potentially exposing private user files to unauthorized parties. The CVSS score of 6.5 reflects a medium severity impact with high confidentiality impact but no integrity or availability impact.

No official patch or remediation is currently available. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is provided, restrict access to the affected API endpoints through network controls or authentication proxies where possible, and monitor for unauthorized access attempts.