GHSA-x223-p2gf-v735: Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak

Summary

Langflow's deprecated POST /api/v1/upload/{flow_id} endpoint in langflow/api/v1/endpoints.py had no authentication and no validation of flow_id, so unauthenticated users with network access could upload unlimited data. The upload wrote to local disk, enabling space exhaustion and denial of service, and the response disclosed the absolute server path of the uploaded file, an information leak. The issue was tested on commit 2d67402b1dbaefcbce85a244d4a6cd5e4bda1cfe.

Mitigation

Fixed in 1.9.1 via PR #12831. The endpoint now uses the get_flow dependency, requiring an authenticated user and flow ownership, and enforces the max_file_size_upload limit (HTTP 413). Upgrade to 1.9.1 or later. The response still returns file_path, but only to the authenticated flow owner.

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

• langflowPyPIReaches an LLM package through dependencies

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