Citrix NetScaler patches a critical remote authentication bypass (CVSS 9.3) exploitable without credentials

On August 19, 2026, Cloud Software Group published a bulletin for NetScaler ADC and NetScaler Gateway: CVE-2026-19490, a CVSS 9.3 authentication bypass exploitable remotely without credentials, and CVE-2026-19489, an 8.8 denial-of-service. Any internet-facing appliance needs an emergency upgrade, after triage driven by the SAML or vserver configuration.