VDB
KO
HIGH

GHSA-5gf6-gc35-xjpc

MCP Toolbox for Databases: authenticated authorization bypass

Details

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).

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Affected packages

Go / github.com/googleapis/mcp-toolbox
Introduced in: 0 Fixed in: 1.4.0
Fix go get github.com/googleapis/mcp-toolbox@v1.4.0

References