By Sergiu Gatlan
Publication Date: 2026-08-20 12:14:00
Citrix has warned customers to immediately secure their systems against two vulnerabilities affecting NetScaler Gateway secure remote access solutions and NetScaler ADC networking appliances.
The most severe of the two, tracked as CVE-2026-19490, can allow remote attackers without privileges to bypass authentication when the appliance is configured as an AAA virtual server or as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy), depending on the NetScaler firmware version and whether SAML Action is configured.
Admins can check if an appliance is vulnerable to attacks targeting CVE-2026-19490 by inspecting their NetScaler configuration for SAML action configuration (add authentication samlAction .*) string and Auth or VPN vserver (‘add authentication vserver .*’ and ‘add vpn vserver .*’) strings.
The second, a high-severity memory overflow security flaw tracked as CVE-2026-19489, can be abused by remote unauthenticated threat actors in denial-of-service (DoS)…
