---
id: CVE-2026-9186
title: >-
  IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to
  bypass localhost-only MCP configuration installation by spoofing
  X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config
  files (~/.cursor/m…
summary: >-
  IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to
  bypass localhost-only MCP configuration installation by spoofing
  X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config
  files (~/.cursor/m…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-284
vendor: langflow
product: langflow
affected:
  - 'langflow >= 1.0.0, < 1.11.3'
patched:
  - langflow 1.11.3
published: '2026-09-04'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:45:27.103'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-9186'
references:
  - url: 'https://www.ibm.com/support/pages/node/7285646'
    label: psirt@us.ibm.com
tags:
  - nvd
  - cve.org
epss: 0.00271
epssPercentile: 0.19572
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-08T16:48:36.278568Z'
ingestedAt: '2026-09-08T15:33:26.961Z'
---

## Overview

IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost-only MCP configuration installation by spoofing X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config files (~/.cursor/mcp.json, etc.).

## Affected

- `langflow >= 1.0.0, < 1.11.3`

## Remediation

Upgrade past the affected range:

- `langflow 1.11.3`