Zero-Day Exploitation of Citrix NetScaler ADC and Gateway: CVE-2026-88771 and CVE-2026-88772

Overview On September 27, 2026, Citrix disclosed eight new vulnerabilities affecting NetScaler ADC and NetScaler Gateway, including two critical remote code execution (RCE) vulnerabilities: CVE-2026-88771 and CVE-2026-88772 . Both of these RCE vulnerabilities carry a critical CVSSv4 score of 9.5, and both have been confirmed as being actively exploited in the wild as zero-days prior to the vendor disclosure . CVE-2026-88771 affects vulnerable NetScaler deployments in their default configuration, with no additional product features required.