Critical Zero-Day Vulnerabilities Exploited in Citrix NetScaler ADC, Gateway

Update October 2, 2026: CISA has updated this Alert to provide a SIGMA detection rule resource to help identify potentially suspicious activity. CISA is amplifying Citrix’s disclosure of eight new vulnerabilities affecting Citrix NetScaler ADC and Citrix NetScaler Gateway products: CVE-2026-88771 , CVE-2026-88772 , CVE-2026-88773 , CVE-2026-88774 , CVE-2026-88775 , CVE-2026-88776 , CVE-2026-88777 , and CVE-2026-88778 . CISA has added CVE-2026-88771 and CVE-2026-88772 to its Known Exploited Vulnerabilities (KEV) Catalog .