CVE-2025-6543

Name of the Vulnerable Software and Affected Versions NetScaler ADC (affected versions not specified) NetScaler Gateway (affected versions not specified)

Description A memory overflow vulnerability exists in NetScaler ADC and NetScaler Gateway when configured as an AAA virtual server or as a Gateway, including VPN virtual servers, ICA Proxy, CVPN, and RDP Proxy. This issue can lead to unintended control flow, Denial of Service, and unauthenticated remote code execution. The flaw has been exploited as a zero-day since May 2025, with reported incidents targeting Dutch organizations such as the OM.

Recommendations Update NetScaler ADC and NetScaler Gateway to the versions released on June 25, 2025. Implement multi-factor authentication (MFA). Enable continuous system monitoring. Isolate affected systems to minimize risk.