CVE-2026-19490: Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability

Required action (CISA's text)

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.

Description (NVD)

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.

SOURCES

• CISA KEVCISA Known Exploited Vulnerabilities catalog

Other Citrix flaws

• CVE-2026-88779: Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
• CVE-2026-88772: Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
• CVE-2026-88771: Citrix NetScaler Improper Input Validation Vulnerability
• CVE-2026-8452: Citrix NetScaler ADC and NetScaler Gateway Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
• CVE-2026-3055: Citrix NetScaler Out-of-Bounds Read Vulnerability

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.