MCP Toolbox for Databases: authenticated authorization bypass

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.6 · 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 · score source

EPSS

• CVE-2026-11719: 0.14% estimated exploitation activity in the next 30 days; percentile 3.78 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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).

Published by the source

18 Jun 2026, 15:32 UTC

Last modified by the source

19 Jun 2026, 17:00 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5gf6-gc35-xjpc

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# Patch Next advisory brief: CVE-2026-11719

Advisory: MCP Toolbox for Databases: authenticated authorization bypass
IDs: CVE-2026-11719, GHSA-5gf6-gc35-xjpc
Record: https://patchnext.com/advisories/cve-2026-11719 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/googleapis/mcp-toolbox 1.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/googleapis/mcp-toolbox: affected < 1.4.0; fixed in 1.4.0

## Suggested inspection (read-only)
- Go github.com/googleapis/mcp-toolbox: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/googleapis/mcp-toolbox.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-5gf6-gc35-xjpc (GitHub-reviewed advisory GHSA-5gf6-gc35-xjpc lists affected ranges: Go github.com/googleapis/mcp-toolbox >=0 <1.4.0)

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