CVE-2026-11719 MCP Toolbox for Databases: authenticated authorization bypass
Authenticated low-privilege users can bypass scope restrictions and execute high-privilege tools by using older protocol versions in MCP Toolbox for Databases.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-11719?
CVE-2026-11719 is a high-severity missing authorization vulnerability in MCP Toolbox for Databases (googleapis/mcp-toolbox), published on 18 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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).
Weakness: CWE-862
Which versions are affected by CVE-2026-11719?
3 open source packages ship an affected version, including github.com/googleapis/mcp-toolbox. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/googleapis/mcp-toolbox Go | All versions | 1.4.0 |
github.com/googleapis/mcp-toolbox Go | All versions | 1.4.0 |
github.com/googleapis/mcp-toolbox Go | All versions | 1.4.0 |
Products include Google Mcp Toolbox for Databases.
How do I fix CVE-2026-11719?
Upgrade github.com/googleapis/mcp-toolbox to 1.4.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-11719 being exploited?
There is no known exploitation of CVE-2026-11719 in the wild and no public exploit code.
Other vulnerabilities in MCP Toolbox for Databases (googleapis/mcp-toolbox)
- CVE-2026-11720 Path Traversal in googleapis/mcp-toolbox HTTP Tool URL Builder
- CVE-2026-11717 googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken)
- CVE-2026-11718 googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken)
- CVE-2026-15829 SQL Injection and Security Boundary Bypass in googleapis/mcp-toolbox
- CVE-2026-14537 Authorization Bypass in MCP Toolbox Legacy HTTP Endpoints
Sources
Also known as GHSA-5gf6-gc35-xjpc, GO-2026-5144.