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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-7663
StatePUBLISHED
Assigneribm
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-30 20:17:31 UTC
Updated2026-07-02 18:19:34 UTC
DescriptionIBM 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.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.002590000 probability, percentile 0.172090000 (date 2026-07-05)

Problem Types: CWE-285 | CWE-863 | CWE-285 CWE-285 Improper Authorization

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1[email protected]Secondary9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
3.1CNACVSS9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Langflow Langflow All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA IBM Langflow OSS affected 1.0.0 1.9.6 semver Not specified

References

ReferenceSourceLinkTags
www.ibm.com/support/pages/node/7277570 [email protected] www.ibm.com Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Solutions

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

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