Skip to content
OpenAdvisories
High · 8.6 CVE-2026-11719 EUVD-2026-37881GHSA-5gf6-gc35-xjpcGO-2026-5144

MCP Toolbox for Databases: authenticated authorization bypass

Published Jun 18, 2026 · Updated Jun 18, 2026 · Assigned by Google

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).

Affected products

VendorProductAffectedFixed
Google MCP Toolbox for Databases (googleapis/mcp-toolbox) 1.3.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/googleapis/mcp-toolbox < 1.4.0 1.4.0 GHSA-5gf6-gc35-xjpc

Advisories 1

References