CISA Warns of Active Exploitation in Citrix NetScaler DoS Vulnerability

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added a high-severity memory overflow vulnerability, CVE-2026-88779, in Citrix NetScaler ADC and Gateway to its Known Exploited Vulnerabilities catalog. This flaw, which can cause denial-of-service (DoS) under specific conditions, is actively being exploited in targeted attacks. Citrix has released security updates, urging federal agencies to apply patches by October 7, 2026, to mitigate the risk.