CVE-2026-11719 | An authenticated authorization bypass vulnerability exists i… | CVSS 8.6 HIGH

Description

An authenticated authorization bypass vulnerability exists in MCP Toolbox for Databases due to missing scope enforcement across older protocol handlers. While the 2025-11-25 protocol version handler correctly enforces per-tool restrictions defined by scopesRequired, older supported protocol versions (2025-06-18, 2025-03-26, and 2024-11-05) omit this check. An authenticated client with low-privilege tokens (e.g., read) can bypass the intended per-tool scope restrictions and execute high-privilege tools (e.g., admin) simply by specifying an older protocol version in the MCP-Protocol-Version header, or by omitting the header entirely (which causes the server to default to the vulnerable 2024-11-05 handler).

Metadata

CVE ID: CVE-2026-11719
State: PUBLISHED
Assigner: Google
Reserved: 2026-06-09 00:53 UTC
Published: 2026-06-18 11:55 UTC
Last updated: 2026-06-18 13:53 UTC
Primary CWE: CWE-862
CWE-862: Missing Authorization
Vendor / Product: Google / MCP Toolbox for Databases (googleapis/mcp-toolbox)
Sources: cve.org · NVD

Severity & Metrics

8.6 HIGH CVSS 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
Google	MCP Toolbox for Databases (googleapis/mcp-toolbox)	—	1.3.0

Weakness (CWE)

CWE	Source	Description
CWE-862	cna	CWE-862: Missing Authorization

CVSS scores (1)

Score	Severity	Version	Source	Vector
8.6	HIGH	4.0	cna	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

References (2)