PT-2026-50661 · Google · Mcp Toolbox For Databases

He Wei（ギカク） · Published 2026-06-18 · Updated 2026-06-18 · CVE-2026-11719

NVD

CVSS v4.0

8.6

High

Base vector

AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/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 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).

Fix

Missing Authorization

Weakness Enumeration

CWE-862

Related Identifiers

CVE-2026-11719

Affected Products

Mcp Toolbox For Databases

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-11719 · Security Note
• https://github.com/googleapis/mcp-toolbox/pull/3049 · Note
• https://github.com/googleapis/mcp-toolbox/pull/3335 · Note
• https://twitter.com/ptdbugs/status/2067629310077235322 · Twitter Post