CVE-2026-14538
Medium
Elevated severity or exploit probability.
CVSS base
7.7
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
EPSS — probability of exploitation (30 days)
0.2%
8.5th percentile
CISA KEV
Not listed
Weakness / dates
CWE-285
Published 2026-07-31 · modified 2026-08-08
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | C | Changed |
| Confidentiality | H | High |
| Integrity | N | None |
| Availability | N | None |
Timeline
- 2026-07-31 — Published (NVD)
- 2026-08-08 — Last modified (NVD)
Description
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.