PYSEC-2026-4234 Langflow : Cross-user flow access and vertex execution via deprecated /api/v1/build/{flow_id}/vertices endpoints

Summary Before Langflow 1.10.1, two deprecated but still-routed endpoints in the chat API did not check that the authenticated caller owns the flow referenced in the URL path: - POST /api/v1/build/flowid/vertices retrieveverticesorder - POST /api/v1/build/flowid/vertices/vertexid buildvertex Any...