Citrix Issues Urgent Patch for New NetScaler Zero-Day Vulnerability Under Active Exploitation

Citrix has released emergency security updates to address a newly discovered NetScaler vulnerability, tracked as CVE-2026-88779, which is actively being exploited in targeted attacks. The memory buffer flaw, rated 8.7 on the CVSS severity scale, affects NetScaler ADC and NetScaler Gateway appliances configured for SAML authentication with Gateway or AAA functionality. Exploitation of this vulnerability can lead to denial-of-service conditions.