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

Warning: Two Unpatched Citrix NetScaler RCE Zero-Days Under Active Exploitation Swati KhandelwalSep 27, 2026Vulnerability / Network Security Two new unpatched zero-day vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway appliances that allow remote code execution are being actively exploited in the wild, security firm watchTowr said on September 26. Citrix has not confirmed the flaws or published a fix. Some administrators say they have taken appliances offline rather than wait for one to be available. NetScaler ADC and NetScaler Gateway sit at the edge of enterprise networks, where they handle VPN and remote access, load balancing, and user authentication. The new flaws are not the authentication bypass, CVE-2026-19490, that Citrix fixed on August 19 and that CISA added to its…