CVE-2026-42048

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 1.9.0 allows any authenticated user to achieve Remote Code Execution (RCE) on the server by adding an MCP server with the "Stdio" transport. The user-supplied command field is passed directly to bash -c "exec {command}" with zero validation, no allowlisting, and no sandboxing. The command executes immediately when the server list is fetched. Additionally, the env field allows arbitrary environment variable injection (e.g., LD_PRELOAD, PATH override).

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.

Code Injection vulnerability in langflow up to 1.9.3. An authenticated attacker can execute arbitrary Python code on the server by submitting malicious code to the /api/v1/validate/code endpoint, which executes code without sandboxing.

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 is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.7.0.dev45, multiple critical API endpoints in Langflow are missing authentication controls. The issue allows any unauthenticated user to access sensitive user conversation data, transaction histories, and perform destructive operations including message deletion. This affects endpoints handling personal data and system operations that should require proper authorization. Version 1.7.0.dev45 contains a patch.