CVE-2026-9186

CVE-2026-9186

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.).

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-9186?
CVE-2026-9186 is a medium-severity vulnerability, classified under Improper Access Control. CVSS score: 6.5/10. Published 2026-09-04.
How severe is CVE-2026-9186?
Medium severity. CVSS v3 base score is 6.5 out of 10.