Hackers exploit Citrix NetScaler zero-day to deploy web shells
Summary
Attackers have exploited a zero-day vulnerability, identified as CVE-2026-88772, in Citrix NetScaler devices. This exploitation allowed them to deploy web shells and tunneling malware, achieve root access, steal credentials, and subsequently move laterally within internal networks.
IFF Assessment
The exploitation of a zero-day vulnerability allows attackers to gain unauthorized access and control, posing a significant threat to organizations.
Severity
CISA KEV: Listed as actively exploited. Federal patch due: September 30, 2026. Known ransomware use: Unknown.
Defender Context
This incident highlights the critical need for organizations to promptly patch or mitigate vulnerabilities in their network infrastructure, especially for widely used devices like Citrix NetScaler. Defenders should monitor for indicators of compromise related to web shell deployment and unauthorized network lateral movement.