{
  "id": "cve-2026-19490",
  "cveID": "CVE-2026-19490",
  "vendor": "Citrix",
  "product": "NetScaler",
  "vulnerabilityName": "Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability",
  "shortDescription": "Citrix NetScaler ADC and NetScaler Gateway contain an authentication-bypass vulnerability involving an alternate path or channel. When the NetScaler appliance is configured as an AAA virtual server or as a Gateway (SSL VPN, ICA Proxy, CVPN, or RDP Proxy), an unauthenticated remote threat actor may be able to bypass authentication.",
  "requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
  "dateAdded": "2026-09-09",
  "dueDate": "2026-09-12",
  "knownRansomware": false,
  "cwes": [
    "CWE-288"
  ],
  "notes": "https://support.citrix.com/external/article/CTX696939/netscaler-adc-and-netscaler-gateway-secu.html ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-19490",
  "sources": [
    {
      "label": "NVD",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19490"
    },
    {
      "label": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog"
    },
    {
      "label": "support.citrix.com",
      "url": "https://support.citrix.com/external/article/CTX696939/netscaler-adc-and-netscaler-gateway-secu.html"
    },
    {
      "label": "cisa.gov",
      "url": "https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk"
    },
    {
      "label": "cisa.gov",
      "url": "https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk"
    },
    {
      "label": "nvd.nist.gov",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19490"
    }
  ],
  "cvss": {
    "score": 9.3,
    "severity": "CRITICAL",
    "version": "4.0",
    "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  },
  "epss": {
    "score": 0.03372,
    "percentile": 0.88028
  },
  "timeline": [
    {
      "date": "2026-09-09",
      "event": "Added to the CISA KEV catalog"
    },
    {
      "date": "2026-09-12",
      "event": "CISA remediation due date (BOD 22-01)"
    }
  ],
  "status": "active"
}