Executive brief
IBM Langflow is an open-source application composition platform used for building AI workflows and integrations. A path traversal vulnerability allows unauthenticated attackers to read arbitrary files from the server by manipulating file paths in API requests, potentially exposing sensitive configuration, credentials, and application data without requiring authentication or user interaction.
Technical details
The vulnerability is a path traversal (CWE-22) in the public flow-build endpoint that fails to properly validate the files parameter before forwarding it to the storage backend. The traversal payload is routed through an unvalidated flow_id storage segment, bypassing existing path-containment guards. Attack preconditions are minimal—no authentication or user interaction is required, only network access to the vulnerable endpoint. An attacker can craft requests with directory traversal sequences (e.g., ../) to read files outside the intended directory, such as configuration files, secrets, or other sensitive data. The vendor (IBM) has released version 1.11.2 as a patch.
Affected products
- IBM Langflow OSS 1.0.0 through 1.11.1
Timeline
- 2026-08-28: disclosed
- 2026-08-21: patched: IBM Langflow OSS version 1.11.2 contains the fix