Citrix reports multiple vulnerabilities in NetScaler ADC and Gateway

Citrix has published a security bulletin covering multiple vulnerabilities in NetScaler ADC and NetScaler Gateway, with CVSSv4 scores from 6.9 to 8.8. Successful exploitation may allow reading data from memory, reading arbitrary files or denial of service, depending on the vulnerability. The most severe are CVE-2026-8451, CVE-2026-8452, CVE-2026-8655 and CVE-2026-13474. Exploitation depends on the appliance configuration, but the CVSSv4 vectors state that no prior authentication is required. No confirmed exploitation was known at the time of publication.

What this means for your organisation

NetScaler typically sits at the edge of the architecture and terminates access for both employees and customers. That makes the appliance both attractive and exposed, and historically Citrix vulnerabilities have drawn attacker attention quickly once details are public. Because exploitation depends on configuration, noting the version number is not enough; somebody has to review the actual setup.

Berigo recommends

• Work through the Citrix bulletin and establish whether your appliances run the affected configurations.
• Schedule the NetScaler update into the next maintenance window, and plan for downtime rather than deferring.
• Review who holds administrative access to the appliances and restrict it to defined sources.
• Have a plan for maintaining user access if the appliance has to be taken offline at short notice.

Source

• support.citrix.com