CVE-2026-7663

Unauthenticated Cross-User MCP Resource Access and Tool Execution via Streamable Transport Authorization Bypass

Published Jun 30, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
IBM Langflow OSS 1.0.0 through 1.9.6 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.

Remediation

Vendor Solution

IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.10.0 https://pypi.org/project/langflow/

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description IBM Langflow OSS 1.0.0 through 1.9.6 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.
Title Unauthenticated Cross-User MCP Resource Access and Tool Execution via Streamable Transport Authorization Bypass
First Time appeared Ibm
Ibm langflow Oss
Weaknesses CWE-285
CPEs cpe:2.3:a:ibm:langflow_oss:1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:langflow_oss:1.9.6:*:*:*:*:*:*:*
Vendors & Products Ibm
Ibm langflow Oss
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
ibm
Published
Updated
Jul 1, 2026, 3:56 AM
Reserved
May 1, 2026, 7:43 PM
Status
Analyzed
Published
Jun 30, 2026, 8:17 PM
Modified
Oct 25, 2026, 9:10 PM