CVE-2026-14541

An authentication bypass and audience confusion vulnerability exists in the Google OAuth provider component of Google mcp-toolbox version 1.4.0. When a Google authService is initialized with mcpEnabled: true but lacks an explicitly defined audience or clientId, the ValidateMCPAuth pipeline for opaque tokens skips audience validation entirely. As a result, the toolbox will accept any valid Google OAuth access token—even those minted for unrelated ecosystem applications—granting unauthorized clients access to protected tools and data backends.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/googleapis/mcp-toolbox/pull/3450	Issue Tracking Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:google:mcp_toolbox_for_databases:1.4.0:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-07-31 03:16

Updated : 2026-08-08 00:06

NVD link : CVE-2026-14541

Mitre link : CVE-2026-14541

CVE.ORG link : CVE-2026-14541

JSON object : View

Products Affected

google

mcp_toolbox_for_databases

CWE

CWE-287

Improper Authentication

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