CVE-2026-9739Vulnerable to DNS rebinding attacks when using SSE (http://b/499408790).
Updated under an hour ago ()
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It affects Google MCP Toolbox for Databases. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 9.4 CRITICAL (v4.0, CNA)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
- Weakness (CWE)
- CWE-942
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- NVD analysis
- Awaiting Analysis
- Record last updated
- May 28, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Google MCP Toolbox for Databases google:mcp_toolbox_for_databases (from the name) | before PR 3054 (Fix CORS bypass) | CNA record |
References
- https://github.com/googleapis/mcp-toolbox/issues/3053
- https://github.com/googleapis/mcp-toolbox/pull/3054
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.