Description
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. This vulnerability is fixed in 1.10.3.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| langflow-ai | langflow | >= 1.5.0, < 1.10.3 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | langflow | >= 1.5.0, < 1.10.3 | 1.10.3 | GHSA-4f6c-2vvp-gw82 |
Advisories 1
- WID-SEC-2026-2837 Langflow: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen und Manipulation von Daten BSI CERT-Bund (WID) · Oct 5, 2026
References
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-4f6c-2vvp-gw82
- https://github.com/langflow-ai/langflow/pull/13915
- https://github.com/langflow-ai/langflow/commit/1f39a4b9d62c9dfa1b21fa7f85e23a180c351b72
- https://github.com/langflow-ai/langflow/commit/94859df33acd70b2a1f816e26d68f5e89a7e5639
- https://github.com/langflow-ai/langflow/releases/tag/v1.10.3