CVE-2026-11719: High severity MCP Toolbox for Databases vulnerability
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).
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
go/github.com/googleapis/mcp-toolboxto a version that resolves this vulnerability.Fixed in 1.4.0 - Upgrade
Upgrade
MCP Toolbox for Databasesto a version that resolves this vulnerability.Fixed in 2025-11-25 - Compensating control
Disallow clients from using the MCP-Protocol-Version header values 2025-06-18, 2025-03-26, or 2024-11-05, and block requests that omit the MCP-Protocol-Version header (since omission defaults to the vulnerable 2024-11-05 handler).
Event History
Frequently Asked Questions
What is the severity of CVE-2026-11719?
The severity of CVE-2026-11719 is rated at 71 on the risk scale.
How do I fix CVE-2026-11719?
To fix CVE-2026-11719, ensure that you upgrade to the latest version of MCP Toolbox for Databases that includes proper scope enforcement.
What type of vulnerability is CVE-2026-11719?
CVE-2026-11719 is an authenticated authorization bypass vulnerability.
Which software is affected by CVE-2026-11719?
CVE-2026-11719 affects the MCP Toolbox for Databases.
What causes the vulnerability in CVE-2026-11719?
The vulnerability in CVE-2026-11719 is caused by missing scope enforcement across older protocol handlers.