# CVE-2026-14540: Server-Side Request Forgery via Unrestricted HTTP Redirection in MCP Toolbox

> Attackers can force the MCP Toolbox to make unauthorized requests to internal or external endpoints via unsafe HTTP redirection handling.

- **Severity:** High 8.0 (`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/E:U`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Jul 2026
- **Updated:** 31 Jul 2026
- **Also known as:** GHSA-3x3x-8ffg-ghcv

## What is CVE-2026-14540?

CVE-2026-14540 is a high-severity server-side request forgery vulnerability in Google mcp-toolbox, published on 31 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A Server-Side Request Forgery (SSRF) vulnerability exists in the generic HTTP source and tool components of Google mcp-toolbox versions 0.3.0 through 1.4.0. While the toolbox implements baseline input sanitization for user-controlled parameters, the underlying HTTP client (internal/sources/http/http.go) fails to safely regulate request redirection boundaries. Specifically, the client is initialized without a restrictive CheckRedirect policy hook and lacks target IP validation. An attacker or a malicious data-driven prompt can supply a crafted path parameter that triggers an open redirect or a direct destination swap on the target backend, coercing the mcp-toolbox into blindly following the redirection and making unauthorized requests to internal or arbitrary external endpoints.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-14540?

It affects 1 product.


Products: Google Mcp Toolbox for Databases.

## How do I fix CVE-2026-14540?

No fix has been published for CVE-2026-14540 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-14540 being exploited?

There is no known exploitation of CVE-2026-14540 in the wild and no public exploit code.

## Other vulnerabilities in Google mcp-toolbox

- [CVE-2026-11720](https://insights.sbomify.com/CVE-2026-11720/): Path Traversal in googleapis/mcp-toolbox HTTP Tool URL Builder (critical 9.3)
- [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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-14540 and fix it if it is affected.

What it is: CVE-2026-14540 is a high-severity server-side request forgery vulnerability in Google mcp-toolbox, published on 31 Jul 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-2026-14540 in the wild and no public exploit code.

Affected product: Google mcp-toolbox. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-14540/ (Markdown: https://insights.sbomify.com/CVE-2026-14540/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-14540
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-14540
- OSV: https://osv.dev/vulnerability/CVE-2026-14540

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-14540/
Summaries are generated and may contain mistakes; the official description above is the record.