CVE-2026-105741 Langflow: IP Spoofing Bypass via `X-Forwarded-For` Allowing Remote Configuration Write
Authenticated attackers can bypass local-only restrictions via IP spoofing to overwrite MCP configuration files on the server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-105741?
CVE-2026-105741 is a high-severity vulnerability in langflow-ai langflow, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Which versions are affected by CVE-2026-105741?
3 open source packages ship an affected version, including langflow.
| Package | Affected | Fixed in |
|---|---|---|
langflow PyPI | From 1.5.0 | 1.10.3 |
langflow PyPI | From 1.5.0 | 1.10.3 |
langflow PyPI | From 1.5.0 | 1.10.3 |
How do I fix CVE-2026-105741?
Upgrade langflow to 1.10.3 or later.
Is CVE-2026-105741 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105741 exists.
Sources
Also known as GHSA-4f6c-2vvp-gw82, PYSEC-2026-4229.