CVE-2026-7664 IBM CVE debrief

Who should care

Organizations using IBM Langflow OSS versions 1.0.0 through 1.8.4 should prioritize patching this vulnerability. The critical severity and potential for unauthenticated access make it essential for defenders to take immediate action. Reviewing and applying the vendor advisory is crucial to prevent potential exploitation.

Technical summary

The vulnerability in IBM Langflow OSS is caused by improper authorization enforcement in the Streamable MCP transport endpoint. This allows unauthenticated attackers to access protected MCP project resources and execute MCP operations. The CVSS vector for this vulnerability is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating a high impact on confidentiality, integrity, and availability. The CWE for this vulnerability is CWE-287, related to improper authentication.

Defensive priority

This vulnerability has a critical CVSS score of 9.8 and allows unauthenticated access, making it a high priority for defenders to patch. Immediate action is recommended to prevent potential exploitation.

Recommended defensive actions

• Review and apply the vendor advisory provided by IBM.
• Update IBM Langflow OSS to a version outside the affected range (1.0.0 through 1.8.4).
• Implement additional monitoring and logging to detect potential exploitation attempts.
• Review and adjust authorization settings for the Streamable MCP transport endpoint.
• Consider compensating controls, such as network segmentation or access restrictions, until patching can be applied.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability, including its CVSS score and CWE classification. The vendor advisory from IBM offers mitigation guidance. The CVE-2026-7664 record was published on June 22, 2026, and last modified on June 26, 2026.

Official resources