CVE-2026-9739_CVE-2026-9739

{
    "lastseen": "",
    "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.",
    "published": "2026-05-27T21:38:55.833Z",
    "modified": "2026-05-27T21:38:55.833Z",
    "type": "cve",
    "title": "CVE-2026-9739",
    "source": "Google",
    "references": "https://github.com/googleapis/mcp-toolbox/issues/3053\nhttps://github.com/googleapis/mcp-toolbox/pull/3054",
    "id": "CVE-2026-9739",
    "bulletinFamily": "",
    "cwe": [
        "CWE-942"
    ],
    "cvelist": null,
    "sourceData": "Google MCP Toolbox for Databases 0",
    "sourceHref": "",
    "cvss": {
        "score": 9.4,
        "severity": "CRITICAL",
        "vector": "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",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "MCP Toolbox for Databases",
    "version": "0",
    "vendor": "Google",
    "ai_description": "DNS rebinding vulnerability in MCP Toolbox for Databases",
    "ai_severity": "Critical",
    "ai_vendor": "Google",
    "ai_product": "MCP Toolbox for Databases",
    "ai_version": "0",
    "ai_score": 9.4
}