CVE-2026-105740

Langflow is a tool for building and deploying AI-powered agents and workflows. From 1.5.0 until 1.10.3, an IP spoofing vulnerability in the Model Context Protocol (MCP) configuration installation endpoint (POST /api/v1/mcp/project/{project_id}/install) allowed authenticated remote attackers to bypass the "local-only" access restriction. By sending a spoofed X-Forwarded-For: 127.0.0.1 header, an attacker could make the server treat the request as originating from localhost, letting them write/overwrite an MCP client configuration file on the server's filesystem.

Langflow is a tool for building and deploying AI-powered agents and workflows. From 1.6.8 until 1.9.1, Langflow authenticated access to the project identifier in a project-scoped MCP connection but did not authorize the resource URI supplied to resources/read. read_resource forwarded the attacker-controlled URI to handle_read_resource, which parsed a flow_id and filename and called storage_service.get_file without verifying that the flow belonged to the authenticated user or current project. A user with access to any project-scoped MCP endpoint could therefore request another user's flow-backed file, while global handle_list_resources and handle_list_tools behavior could disclose flow and file identifiers that made targeting easier.

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.

Langflow prior to version 1.5.1 had a security vulnerability that allowed authenticated users to access other users' flows without ownership checks. The issue stemmed from the lack of proper query filtering based on the `AUTO_LOGIN` setting.

Langflow before 1.10.3 launches whatever command / args a user put in an MCP server configuration, with no allowlist and (before 1.10.3) wrapped in bash -c "exec {command} ...". Any user able to reach the MCP server settings or to build a flow with the MCP Tools component could add a "server" whose command is an arbitrary OS command. The command runs on the Langflow host as the Langflow process user as soon as Langflow tries to connect to the server. With the default LANGFLOW_AUTO_LOGIN=true, GET /api/v1/auto_login hands out a token without credentials, so on an exposed instance running the default configuration this is reachable without an account. With AUTO_LOGIN disabled, any authenticated (non-admin) user can exploit it.

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.9.1, unauthenticated users can upload unlimited amounts of data to the server, leading to space exhaustion. Additionally, the server response reveals the absolute path of the uploaded file, which constitutes an information leak.

Langflow, a tool for building and deploying AI agents, is vulnerable to Path Traversal in the Knowledge Bases API (DELETE /api/v1/knowledge_bases) prior to version 1.9.0. An attacker can exploit this flaw to delete arbitrary directories on the server.