What is CVE-2026-7664?

CVE-2026-7664 is a critical-severity vulnerability in IBM Langflow Oss, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-06-22.

How severe is CVE-2026-7664?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in IBM Langflow Oss

CVE-2026-7664

IBM Langflow OSS 1.0.0 through 1.8.4 could allow unauthenticated attackers to access protected MCP project resources and execute MCP operations due to improper authorization enforcement in the Streamable MCP transport endpoint.

Vulnerability class: Broken Authentication

Published 2026-06-22 · last modified 2026-06-26.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (40.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

IBM Langflow Oss — versions 1.0.0
Langflow

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

www.ibm.com/support/pages/node/7277243 (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-7664?: CVE-2026-7664 is a critical-severity vulnerability in IBM Langflow Oss, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-06-22.
How severe is CVE-2026-7664?: Critical severity. CVSS v3 base score is 9.8 out of 10.