Langflow OSS vulnerability

IBM Langflow OSS 1.0.0 through 1.11.5 allows an authenticated non-administrative user could execute arbitrary operating system commands on the server at the privilege level of the application process by constructing a flow with an MCP Tools component configured to use a local stdio subprocess transport. This bypasses both the LANGFLOW_CUSTOM_COMPONENT_ADMIN_ONLY and LANGFLOW_BLOCK_CODE_INTERPRETER_COMPONENTS server-side controls intended to prevent exactly this class of access. Successful exploitation could lead to arbitrary command execution, sensitive data exposure (including credentials from the process environment), file system modification, and lateral movement to services reachable from the server.

Published 10 Sep 2026Updated 12 Sep 20261 sources
CVSS 8.8

What happened

IBM Langflow OSS 1.0.0 through 1.11.5 allows an authenticated non-administrative user could execute arbitrary operating system commands on the server at the privilege level of the application process by constructing a flow with an MCP Tools component configured to use a local stdio subprocess transport. This bypasses both the LANGFLOW_CUSTOM_COMPONENT_ADMIN_ONLY and LANGFLOW_BLOCK_CODE_INTERPRETER_COMPONENTS server-side controls intended to prevent exactly this class of access. Successful exploitation could lead to arbitrary command execution, sensitive data exposure (including credentials from the process environment), file system modification, and lateral movement to services reachable from the server.

Affected versions

Langflow OSS: 1.0.0 through 1.11.5 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.