CVE-2026-14538 BigQuery Dataset Allowlist Bypass via Metadata Dry-Run in MCP Toolbox

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 enfor...