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CVE-2023-4966

CRITICAL severity · CVSS 9.4 · Memory corruption · actively exploited (CISA KEV)
9.4CVSS CRITICAL ● exploited ⚠ ransomware
🔴 Actively exploited in the wild (CISA Known Exploited Vulnerabilities). ⚠ Known use in ransomware campaigns. Added to KEV 2023-10-18. US federal agencies must patch by 2023-11-08.

Summary

Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA  virtual server.

Impact & exploitability

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactLow
Exploit probability (EPSS)94%

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

Affected products we track (1)

Recommendation

This vulnerability is being actively exploited in the wild — patch affected products urgently. Open any affected product above for its exact safe version.

Last checked: Wed, 10 Jun 2026 22:18:30 UTC