CVE-2026-9186: Langflow

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

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 products

• Langflow Langflow: from 1.0.0, before 1.11.3 (fixed in 1.11.3)

Published 2026-09-04. Last modified 2026-09-08.