Langflow : Cross-user flow access and vertex execution via deprecated /api/v1/build/{flow_id}/vertices endpoints

Why it is Yellow

• CVSS 5.4 medium
• Public exploit or proof of concept referenced
• On your watchlist: PyPI

Affected packages

References

• https://github.com/advisories/GHSA-gh98-4phw-6fmw
• https://github.com/langflow-ai/langflow/security/advisories/GHSA-gh98-4phw-6fmw
• https://nvd.nist.gov/vuln/detail/CVE-2026-105698
• https://github.com/langflow-ai/langflow/pull/13153
• https://github.com/langflow-ai/langflow/commit/fb3d6ec90b1e4d52eaa40915a64b1f86b6542f55
• https://github.com/langflow-ai/langflow/releases/tag/v1.10.1
• https://github.com/advisories/GHSA-gh98-4phw-6fmw

Original description

Langflow is a tool for building and deploying AI-powered agents and workflows. From 1.0.0 until 1.10.1, Langflow did not verify flow ownership in the deprecated POST /api/v1/build/{flow_id}/vertices and POST /api/v1/build/{flow_id}/vertices/{vertex_id} handlers. Through version 1.7.1, an unauthenticated caller who knew another user's flow UUID could reach these handlers; from version 1.7.2 through 1.10.0, callers had to authenticate but needed no elevated privileges. Such a caller could cause retrieve_vertices_order to load and cache the private graph, enumerate its vertex identifiers, and use build_vertex to execute selected vertices and receive their results. build_graph_from_db_no_cache performed a primary-key lookup without an owner filter. This could disclose private flow structure, configured values, and selected outputs and could trigger victim-configured side effects and build-history records, although it did not expose the victim's variable-store credentials or permit modification of the stored flow. This issue is fixed in Langflow 1.10.1 and langflow-base 0.10.1.