Skip to content
OpenAdvisories
Critical · 9.4 CVE-2026-9739 EUVD-2026-32672GHSA-7pf3-8xx7-rvhfGO-2026-5870

MCP Toolbox for Databases vulnerable to DNS rebinding attacks

Published May 27, 2026 · Updated May 28, 2026 · Assigned by Google

Description

Vulnerable to DNS rebinding attacks when using SSE (http://b/499408790). During the beta phase, we implemented `allowed-origins` and `allowed-hosts` flags to align with MCP security guidelines. However, the hardcoded `Access-Control-Allow-Origin: *` header in the SSE initialization handler was inadvertently retained. This vulnerability specifically impacts users connecting via Toolbox using SSE under specification v2024-11-05.

Affected products

VendorProductAffectedFixed
Google MCP Toolbox for Databases < PR 3054 (Fix CORS bypass) PR 3054 (Fix CORS bypass)

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/googleapis/mcp-toolbox < 1.2.0 1.2.0 GHSA-7pf3-8xx7-rvhf

Advisories 1

References