CVE-2023-4966 CRITICAL

CVE-2023-4966: Unauthenticated sensitive information disclosure

Vendor Citrix
Product NetScaler ADC
Weakness CWE-119
KEV Status Known Exploited
Ransomware Used in campaigns
Published October 10, 2023
Last update October 21, 2025
View on NVD All CVEs

CVSS base score

9.4/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

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.

CISA mandated remediation

02CISA Required Action

Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.

Key dates

03Disclosure timeline

October 10, 2023 CVE published
October 21, 2025 Record updated