Vulnerability · Published Oct 5, 2026 · Assigned by GitHub_M
CVE-2026-105741Langflow: IP Spoofing Bypass via `X-Forwarded-For` Allowing Remote Configuration Write
High 7.1
In plain English
A high-severity authentication bypass by spoofing in langflow from langflow-ai. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | langflow | 1.10.3 | GHSA-4f6c-2vvp-gw82 |
| PyPI | langflow | 1.10.3 | PYSEC-2026-4229 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| langflow-ai | langflow | >= 1.5.0, < 1.10.3 |
Weakness: CWE-290, CWE-345 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
References
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-4f6c-2vvp-gw82 x_refsource_CONFIRM
- https://github.com/langflow-ai/langflow/pull/13915 x_refsource_MISC
- https://github.com/langflow-ai/langflow/commit/1f39a4b9d62c9dfa1b21fa7f85e23a180c351b72 x_refsource_MISC
- https://github.com/langflow-ai/langflow/commit/94859df33acd70b2a1f816e26d68f5e89a7e5639 x_refsource_MISC
- https://github.com/langflow-ai/langflow/releases/tag/v1.10.3 x_refsource_MISC