Citrix · NetScaler
CVE-2026-19490
Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability
CISA KEV record
- CISA date added
- 2026-09-09
- CISA due date
- 2026-09-12
- Known ransomware use
- Unknown
NVD risk context
9.3 CRITICAL
CVSS is a technical severity score. CISA’s KEV status remains the evidence that this vulnerability is known to be exploited.
Description
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.
Required action
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.
NVD reference index
Vendor and remediation references
NVD has tagged these sources as vendor advisories, patches, mitigations, or release notes.
Other NVD references (1)
MITRE CWE context
CWE classification
The product requires authentication, but the product has an alternate path or channel that does not require authentication.
View official MITRE CWE details ↗NVD record timing
NVD record timeline
These dates describe NVD’s record, not CISA’s KEV addition or remediation due date.
- NVD published
- Aug 19, 2026, 01:17 PM UTC When NVD first published this CVE record.
- NVD last updated
- Sep 10, 2026, 12:48 PM UTC When NVD last changed its analysis or record data.
Advanced: view the technical CVSS vector
This standardized code is intended for security tools and technical analysts. The plain-language risk summary above explains its main points.
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
CISA 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
- https://support.citrix.com/external/article/CTX696939/netscaler-adc-and-netscaler-gateway-secu.html
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- 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