CVE-2026-19490CitrixFirewall and VPNSeptember 9, 2026

Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability

Critical 9.8Actively 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.

What to do

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.

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Details

Vendor
Citrix
Product
NetScaler ADC e NetScaler Gateway
CVE
CVE-2026-19490
Affected versions
NetScaler ADC 14.1: from 14.1 to 14.1-73.32 (NVD: 73.32 (included); CPE partly lists it as excluded)
NetScaler ADC 13.1: from 13.1 to 13.1-63.21 (NVD: 63.21 (included); CPE lists it as excluded)
NetScaler ADC 13.1: build 13.1-37.x before 13.1-37.277 — fixed in 13.1-37.277
NetScaler Gateway 14.1: from 14.1 to 14.1-73.32 (NVD: 73.32 (included); CPE lists it as excluded)
NetScaler Gateway 13.1: from 13.1 to 13.1-63.21 (NVD: 63.21 (included); CPE lists it as excluded) (from the advisory and NVD; check the exact builds in the official advisory)
CVSS score
9.8
Actively exploited
Yes, listed in the CISA Known Exploited Vulnerabilities catalog
CISA due date
September 12, 2026 (deadline for US federal agencies: a good benchmark for you too)
Source
CISA KEV – original advisory
Published
September 9, 2026

The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.

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