GitHub Advisoryadvisory · Go

GHSA-5gf6-gc35-xjpc MCP Toolbox for Databases: authenticated authorization bypass

HIGH Published 2026-06-18 Modified 2026-06-19 Official page ↗
Aliases
CVE-2026-11719
Ecosystem
Go
Packages
github.com/googleapis/mcp-toolbox
Severity
High
CVSS vector
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
Weaknesses
CWE-862
Reviewed
2026-06-19

Affected packages

• Go github.com/googleapis/mcp-toolbox: < 1.4.0 → fixed in 1.4.0

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).

Related

Alias · CVE (1)

  • CVE-2026-11719 An authenticated authorization bypass vulnerability exists in MCP Toolbox for Databases due to missing scope enforcement across older… vulnerability

Weakness · CWE (1)

  • CWE-862 Missing Authorization weakness

References