---
title: "CVE-2026-11624: MCP Toolbox for Databases has an Origin Validation Error"
url: https://erroneo.us/security/cve/CVE-2026-11624/
description: "CVE-2026-11624 (github.com/googleapis/mcp-toolbox (Go)): The Model Context Protocol has a security warning advising servers to validate the \"Origin\" header…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-13
date_modified: 2026-08-24
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-11624"
kev: false
cvss: 9.4
epss: 0.00219
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-11624: MCP Toolbox for Databases has an Origin Validation Error

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.2% , percentile 12: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 12% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Only applies if your dependency tree includes github.com/googleapis/mcp-toolbox (Go) < 0.25.0, fixed in 0.25.0 . Check your lockfile, including transitive dependencies.

## What it is

The Model Context Protocol has a security warning advising servers to validate the "Origin" header on all incoming connections to prevent DNS rebinding attacks. Prior to the v0.25.0 release, users had no way to validate the origin's host. In v0.25.0, a new "--allowed-hosts" flag was introduced alongside the existing "--allowed-origins" flag, enabling users to specify permitted hosts at server startup. Both flags default to "", allowing users to implement strict access controls as needed without breaking existing setups. If either flag is set to "", the server will output a startup warning about potential vulnerabilities. Documentation has also been updated to highlight these security considerations.

## Affected packages

- Go `github.com/googleapis/mcp-toolbox` < 0.25.0 → fixed: 0.25.0

## Affected products (CVE record)

- Google MCP Toolbox for Databases: < 0.25.0

## Severity

- Google CVSS 4.0: 9.4 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`
- GitHub CVSS 4.0: 9.4 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.22% probability of exploitation activity in the next 30 days; percentile 12.

## Sources

- [GitHub Advisory GHSA-76g7-m3xw-x9gr](https://github.com/advisories/GHSA-76g7-m3xw-x9gr)
- [CVE.org record CVE-2026-11624](https://www.cve.org/CVERecord?id=CVE-2026-11624)
- [NVD entry CVE-2026-11624](https://nvd.nist.gov/vuln/detail/CVE-2026-11624)
- [github.com](https://github.com/googleapis/mcp-toolbox/issues/3113)
- [github.com](https://github.com/googleapis/mcp-toolbox/pull/2254)
- [github.com](https://github.com/googleapis/mcp-toolbox/commit/17b41f64531b8fe417c28ada45d1992ba430dc1b)

---
Source page: https://erroneo.us/security/cve/CVE-2026-11624/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt