Description
An authenticated authorization bypass vulnerability exists in MCP Toolbox for Databases due to missing scope enforcement across older protocol handlers.

While the 2025-11-25 protocol version handler correctly enforces per-tool restrictions defined by scopesRequired, older supported protocol versions (2025-06-18, 2025-03-26, and 2024-11-05) omit this check. An authenticated client with low-privilege tokens (e.g., read) can bypass the intended per-tool scope restrictions and execute high-privilege tools (e.g., admin) simply by specifying an older protocol version in the MCP-Protocol-Version header, or by omitting the header entirely (which causes the server to default to the vulnerable 2024-11-05 handler).
Published: 2026-06-18
Score: 8.6 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-5gf6-gc35-xjpc MCP Toolbox for Databases: authenticated authorization bypass
History

Sun, 21 Jun 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Google
Google mcp Toolbox For Databases
Vendors & Products Google
Google mcp Toolbox For Databases

Thu, 18 Jun 2026 18:15:00 +0000

Type Values Removed Values Added
Title Authenticated Authorization Bypass via Old Protocol Versions in MCP Toolbox for Databases

Thu, 18 Jun 2026 16:45:00 +0000

Type Values Removed Values Added
Description An authenticated authorization bypass vulnerability exists in MCP Toolbox for Databases due to missing scope enforcement across older protocol handlers. While the 2025-11-25 protocol version handler correctly enforces per-tool restrictions defined by scopesRequired, older supported protocol versions (2025-06-18, 2025-03-26, and 2024-11-05) omit this check. An authenticated client with low-privilege tokens (e.g., read) can bypass the intended per-tool scope restrictions and execute high-privilege tools (e.g., admin) simply by specifying an older protocol version in the MCP-Protocol-Version header, or by omitting the header entirely (which causes the server to default to the vulnerable 2024-11-05 handler).
Weaknesses CWE-862
References
Metrics cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Subscriptions

Google Mcp Toolbox For Databases
cve-icon MITRE

Status: PUBLISHED

Assigner: Google

Published:

Updated: 2026-06-18T13:53:08.793Z

Reserved: 2026-06-09T00:53:57.846Z

Link: CVE-2026-11719

cve-icon Vulnrichment

Updated: 2026-06-18T12:55:48.454Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-20T22:56:16Z

Weaknesses