PT-2026-66664 · Google · Mcp-Toolbox

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CVE-2026-14538

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Published

2026-07-31

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Updated

2026-07-31

CVSS v4.0

5.7

Medium

VectorAV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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.

Fix

Improper Authorization

Incorrect Authorization

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Weakness Enumeration

Related Identifiers

CVE-2026-14538

Affected Products

Mcp-Toolbox