CVE-2026-14538

An improper authorization and security-boundary bypass vulnerability in the bigquery-execute-sql tool component of Google mcp-toolbox versions 0.16.1 through 1.4.0 allows an authenticated attacker to bypass allowedDatasets validation checks. The toolbox relies on the BigQuery dry-run API to enforce dataset restrictions, but due to a fail-open logic flaw, it bypasses validation when the API returns an empty array for specialized constructs. This allows the attacker to extract structural DDL schemas for explicitly excluded datasets via INFORMATION_SCHEMA, and access downstream federated row data via EXTERNAL_QUERY connections.

CVSS v3 7.7 HIGH

7.7^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.1 / Impact : 4.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/googleapis/mcp-toolbox/pull/3452	Issue Tracking Patch

Configurations

Configuration 1 (hide)

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

History

No history.

Information

Published : 2026-07-31 02:16

Updated : 2026-08-08 00:25

NVD link : CVE-2026-14538

Mitre link : CVE-2026-14538

CVE.ORG link : CVE-2026-14538

JSON object : View

Products Affected

google

mcp_toolbox_for_databases

CWE

CWE-285

Improper Authorization

CWE-863

Incorrect Authorization

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