On 24 September 2026, GreyNoise observed a malicious actor using 149.104.78.141 to attempt pre-disclosure zero-day exploitation of a Citrix NetScaler Gateway on a Project Swarm participant sensor. No CVE-specific detections existed at the time, but behavioral detections labeled the activity malicious within seconds. The attempt failed to …
CISA added two Citrix NetScaler vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog based on evidence of active exploitation: CVE-2026-88771, an improper input validation flaw, and CVE-2026-88772, a memory buffer bounds restriction flaw. CISA describes these vulnerability types as frequent attack vectors for malicious cyb…
CISA added one vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog on 2026-10-04, citing evidence of active exploitation: CVE-2026-88779, an improper restriction of operations within the bounds of a memory buffer flaw in Citrix NetScaler. CISA describes this vulnerability type as a frequent attack vector for malicious cyber…
Cloudflare published defensive guidance following the disclosure of actively exploited Citrix NetScaler vulnerabilities. CVE-2026-88771 allows unauthenticated command execution on affected appliances, including in the default configuration. CVE-2026-88772 affects configurations using DTLS. Citrix's September 27, 2026 bulletin reported obs…
Mandiant and GTIG attribute exploitation of the critical BeyondTrust Remote Support zero-day CVE-2026-102764 to Armory Castle (formerly tracked as UNC5221), a likely Chinese government-backed espionage group. BeyondTrust dates the first known exploitation to Aug. 29 and says it detected and contained the activity Sept. 28. Only a small nu…
CISA issued an alert on exploitation of critical zero-day vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway, noting confirmed malicious activity involving at least some of them. The alert references Citrix bulletins for CVE-2026-107406, CVE-2026-88779 and CVE-2026-88771 through CVE-2026-88778. Because NetScaler updates can be …