{
  "id": "CVE-2023-4966",
  "url": "https://spydr.io/cve/CVE-2023-4966",
  "published": "2023-10-10T14:15:10.977Z",
  "modified": "2026-07-31T04:16:44.230Z",
  "score": 7.5,
  "severity": "high",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
  "score_source": "NVD",
  "epss": 0.99999,
  "epss_percentile": 0.99997,
  "exploited": true,
  "kev": {
    "added": "2023-10-18",
    "due": "2023-11-08",
    "action": "Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.",
    "ransomware": "Known",
    "name": "Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability",
    "notes": "https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/, https://support.citrix.com/article/CTX579459/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20234966-and-cve20234967 ; https://nvd.nist.gov/vuln/detail/CVE-2023-4966"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "Citrix"
  ],
  "products": [
    "Citrix NetScaler ADC",
    "Citrix NetScaler Gateway"
  ],
  "cwes": [
    "CWE-119"
  ],
  "description": "Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 7.5,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "https://support.citrix.com/article/CTX579459",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4966",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2023-4966",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}