CVE-2026-18899

IBM Langflow OSS versions 1.0.0 through 1.11.1 allow an authenticated attacker to execute arbitrary operating system commands in the server process by saving a flow with a crafted type field value and triggering a build of a wrapper flow that references it. This allows privilege escalation from 'authenticated flow user' to arbitrary OS-level command execution, bypassing the LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false policy.

IBM Langflow OSS versions 1.0.0 through 1.11.1 could allow a remote attacker to execute arbitrary code due to improper enforcement of security restrictions on the A2A public endpoint.

IBM Langflow OSS 1.0.0 through 1.9.6 could allow a remote attacker to obtain unauthorized access to user accounts due to improper restriction of excessive authentication attempts.

IBM Langflow OSS versions 1.0.0 through 1.10.0 could allow a remote attacker to inject arbitrary code on the system due to improper control of user input code.

IBM Langflow OSS versions 1.0.0 through 1.10.1 contain an improper input validation vulnerability in the PythonREPL sandbox implementation.

IBM Langflow OSS versions 1.0.0 through 1.10.1 are vulnerable to unauthenticated remote code execution via environment variable injection in the MCP stdio launcher. The vulnerability is due to an incomplete blocklist of dangerous environment variables (missing SHELLOPTS, BASHOPTS, and PS4) in src/lfx/src/lfx/base/mcp/util.py.

IBM Langflow OSS versions 1.0.0 through 1.10.1 contain hard-coded credentials (passwords or cryptographic keys) used for inbound authentication, outbound communication, or internal data encryption.

IBM Langflow OSS versions 1.0.0 through 1.10.0 allow authenticated users to escalate privileges to superuser by directly manipulating the database, execute arbitrary system commands, and achieve full system compromise with Langflow service permissions.

IBM Langflow OSS 1.0.0 through 1.10.0 has a vulnerability in webhook authentication logic that allows unauthenticated users to trigger execution of any flow when WEBHOOK_AUTH_ENABLE is set to False (default).

Critical vulnerability in IBM Langflow OSS versions 1.0.0 through 1.10.0 in the /api/v1/validate/code endpoint. Allows an authenticated attacker to execute arbitrary Python code on the server without sandboxing, leading to remote code execution.