Citrix NetScaler security snafus get even worse amid more 0-day reports

The attackers just keep coming after Citrix NetScaler appliances, as both the feds and private security researchers warn that someone found - and has already exploited - yet another Citrix bug before it had a patch. This latest vulnerability, tracked as CVE-2026-88779, is a memory overflow bug that leads to denial of service attacks. It only affects NetScaler ADC and Gateway appliances configured as a SAML (Security Assertion Markup Language) service provider or identity provider, used for single sign-on authentication. Late Friday, amid exploitation reports, Citrix confirmed that it was investigating a “newly observed issue related to SAML authentication in customer-managed NetScaler deployments.” By Saturday night, the vendor released a security advisory for NetScaler ADC and NetScaler Gateway with patches, urging vulnerable customers to “install the relevant updated versions as soon as possible.” Citrix also posted a blog about the vulnerability, confirming that it has observed targeted attacks on unmitigated NetScaler deployments that can lead to denial of service. …