CVE-2023-4966
High 7.5 Exploited in the wild (KEV) Used in ransomware campaigns
Confirmed active exploitation — CISA KEV catalog
- Name
- Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability
- Added to catalog
- Remediation due date (US federal)
- 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.
Description
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.
Metrics
- CVSS 3.1
-
7.5 (HIGH)
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 100% (percentile: 100) as of 2 November 2026
- CWE
- CWE-119
Affected products
citrix: netscaler application delivery controller; citrix: netscaler gateway
References
- https://support.citrix.com/article/CTX579459 Vendor Advisory
- https://support.citrix.com/article/CTX579459 Vendor Advisory
- http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-… Third Party AdvisoryVDB Entry
- http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-… Third Party AdvisoryVDB Entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023… US Government Resource