Warning: Two Unpatched Citrix NetScaler RCE Zero-Days Under Active Exploitation

Two unpatched zero-day vulnerabilities in Citrix NetScaler ADC and Gateway are being actively exploited before any vendor fix is available, representing a classic zero-day crisis scenario where defenders are at an inherent disadvantage. The root cause is the absence of a timely vendor patch combined with insufficient compensating controls to protect internet-facing appliances. This matters significantly because NetScaler devices sit at the perimeter of enterprise networks, meaning successful remote code execution can grant attackers a privileged foothold for lateral movement, data exfiltration, or ransomware deployment. The fact that some administrators had to take appliances offline entirely highlights the operational cost of inadequate vulnerability management and emergency response planning.