# CVE-2026-11720: Path Traversal in googleapis/mcp-toolbox HTTP Tool URL Builder

> Attackers can use path traversal in URL construction to access unauthorized endpoints and leak credentials on the target host.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Jun 2026
- **Updated:** 29 Jun 2026
- **Also known as:** GHSA-vwxw-jrg6-9jxv, GO-2026-6411

## What is CVE-2026-11720?

CVE-2026-11720 is a critical path traversal vulnerability in MCP Toolbox for Databases (googleapis/mcp-toolbox), published on 29 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A path traversal vulnerability exists in the HTTP tool URL builder of googleapis/mcp-toolbox.

When constructing downstream API requests, the URL builder substitutes user-controlled pathParams into the configured tool path and parses the resulting string as a relative URL. While it checks that the input does not alter the scheme, host, or user info, it relies on ResolveReference for the final URL resolution. Because dot segments (../) are normalized during this resolution step, an attacker can supply path parameters containing directory traversal sequences to escape the operator-configured path scope. This allows the client to coerce the toolbox into making requests to unintended endpoints on the same target host while forwarding the toolbox's configured credentials (e.g., bypassing a restricted path like /api/v1/users/{{.id}} to reach /admin/secrets).

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-11720?

3 open source packages ship an affected version, including github.com/googleapis/mcp-toolbox. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/googleapis/mcp-toolbox` | Go | All versions | 1.3.0 |
| `github.com/googleapis/mcp-toolbox` | Go | All versions | 1.3.0 |
| `github.com/googleapis/mcp-toolbox` | Go | All versions | 1.3.0 |

Products: Google Mcp Toolbox for Databases.

## How do I fix CVE-2026-11720?

Upgrade github.com/googleapis/mcp-toolbox to 1.3.0 or later.

## Is CVE-2026-11720 being exploited?

There is no known exploitation of CVE-2026-11720 in the wild and no public exploit code.

## Other vulnerabilities in MCP Toolbox for Databases (googleapis/mcp-toolbox)

- [CVE-2026-11717](https://insights.sbomify.com/CVE-2026-11717/): googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken) (critical 9.3)
- [CVE-2026-11718](https://insights.sbomify.com/CVE-2026-11718/): googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken) (critical 9.3)
- [CVE-2026-15829](https://insights.sbomify.com/CVE-2026-15829/): SQL Injection and Security Boundary Bypass in googleapis/mcp-toolbox (high 8.6)
- [CVE-2026-11719](https://insights.sbomify.com/CVE-2026-11719/): MCP Toolbox for Databases: authenticated authorization bypass (high 8.6)
- [CVE-2026-14537](https://insights.sbomify.com/CVE-2026-14537/): Authorization Bypass in MCP Toolbox Legacy HTTP Endpoints (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11720 and fix it if it is affected.

What it is: CVE-2026-11720 is a critical path traversal vulnerability in MCP Toolbox for Databases (googleapis/mcp-toolbox), published on 29 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-11720 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/googleapis/mcp-toolbox (Go): affected all versions; fixed in 1.3.0
- github.com/googleapis/mcp-toolbox (Go): affected all versions; fixed in 1.3.0
- github.com/googleapis/mcp-toolbox (Go): affected all versions; fixed in 1.3.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-11720/ (Markdown: https://insights.sbomify.com/CVE-2026-11720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11720
- OSV: https://osv.dev/vulnerability/CVE-2026-11720

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11720/
Summaries are generated and may contain mistakes; the official description above is the record.