CVE-2026-7663: Unauthenticated Cross-User MCP Resource Access and Tool Execution via Streamable Transport Authorization Bypass

Published Jun 23, 2026
·
Updated

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.

Other sources

Langflow OSS 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.

IBM

Affected Software

3 affected components
IBM Langflow>=1.0.0<=1.9.6
IBM Langflow OSS<=1.0.0 - 1.9.6
Langflow Langflow>=1.0.0<1.10.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Langflow OSS to a version that resolves this vulnerability.

    Fixed in 1.10.0

Event History

Jun 23, 2026
CVE Published
via IBM·12:00 AM
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software
Jun 30, 2026
CVE Published
via MITRE·07:16 PM
Data Sourced
via MITRE·07:16 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·08:17 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2026-7663?

CVE-2026-7663 has a critical severity rating of 9.8.

2

How do I fix CVE-2026-7663?

To mitigate CVE-2026-7663, ensure you update IBM Langflow OSS to the latest version that addresses the vulnerability.

3

What are the risks associated with CVE-2026-7663?

CVE-2026-7663 allows unauthenticated attackers to access protected MCP resources and execute operations, significantly increasing the risk of data compromise.

4

What versions of IBM Langflow are affected by CVE-2026-7663?

CVE-2026-7663 affects IBM Langflow OSS versions from 1.0.0 to 1.9.6.

5

Is authentication required to exploit CVE-2026-7663?

No, CVE-2026-7663 can be exploited by unauthenticated attackers.

Contact

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