CVE-2023-3519: in the CISA KEV catalogue
Citrix NetScaler ADC and NetScaler Gateway Code Injection Vulnerability. CISA added CVE-2023-3519 to the Known Exploited Vulnerabilities catalogue on 2023-07-19 with a default due date of 2023-08-09. Known ransomware campaign use: Known. Forensic triage flag: No.
Citrix NetScaler ADC and NetScaler Gateway contains a code injection vulnerability that allows for unauthenticated remote code execution. (CISA description)
- Vendor / product
- Citrix NetScaler ADC and NetScaler Gateway
- CWE
- CWE-94
- CISA required action
- Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- EPSS
- 100%, percentile 99 (scored 2026-11-03)
EPSS puts nearly every time in 100 odds (100%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 99% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.
Vendor and reference links (from CISA)
Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.
Frequently asked questions
Is CVE-2023-3519 in the CISA KEV catalogue?
Yes. CISA added CVE-2023-3519 (Citrix NetScaler ADC and NetScaler Gateway Code Injection Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2023-07-19. CISA's default due date for it is 2023-08-09.
Is CVE-2023-3519 used in ransomware attacks?
CISA marks known ransomware campaign use as Known for CVE-2023-3519.
What should I do about CVE-2023-3519?
CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Sources
- CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
- FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
- NVD record for CVE-2023-3519