{
    "id": "CVE-2021-31207",
    "published": "2021-05-11 19:15:10",
    "last_modified": "2026-06-17 03:51:27",
    "cvss_score": "6.6",
    "cvss_severity": "MEDIUM",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
    "cwe": "CWE-434",
    "description": "Microsoft Exchange Server Security Feature Bypass Vulnerability",
    "epss_score": "0.99782",
    "epss_percentile": "0.99955",
    "kev": 1,
    "kev_due": "2021-11-17",
    "has_exploit": 0,
    "updated_at": "2026-09-26 18:27:29",
    "priority": {
        "rank": 1,
        "label": "Patch first",
        "why": "On CISA KEV — known exploited in the wild, due 2021-11-17."
    },
    "products": [
        {
            "vendor": "microsoft",
            "product": "exchange_server"
        }
    ],
    "kev_detail": {
        "cve_id": "CVE-2021-31207",
        "date_added": "2021-11-03",
        "due_date": "2021-11-17",
        "vendor": "Microsoft",
        "product": "Exchange Server",
        "name": "Microsoft Exchange Server Security Feature Bypass Vulnerability",
        "ransomware": 1
    },
    "exploits": [],
    "refs_list": [
        "http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html",
        "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31207",
        "https://www.zerodayinitiative.com/advisories/ZDI-21-819/",
        "http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html",
        "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31207",
        "https://www.zerodayinitiative.com/advisories/ZDI-21-819/",
        "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31207"
    ]
}