What it is
CVE-2023-3519 is an unauthenticated Unauthenticated remote code execution affecting Citrix NetScaler ADC, NetScaler Gateway.
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2023-3519
Unauthenticated remote code execution
Citrix / NetScaler ADC · affected before 49.13
- Severity
- CVSS 9.8 · Critical
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 99.7%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
Citrix / NetScaler ADC affected before 49.13.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Unauthenticated remote code execution
Unauthenticated remote code execution
Vendor
Product
Affected
Status
Citrix
NetScaler ADC
Before 49.13
Affected
Citrix
NetScaler ADC
Before 91.13
Affected
Citrix
NetScaler ADC
Before 37.159
Affected
Citrix
NetScaler ADC
Before 55.297
Affected
Citrix
NetScaler ADC
Before 55.297
Affected
Citrix
NetScaler Gateway
Before 49.13
Affected
Citrix
NetScaler Gateway
Before 91.13
Affected
- Published
- 19 Jul 2023
- Exploitation Reported
- 19 Jul 2023
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
ransomware
cisa
malware
metasploit
nuclei_scanner
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2023-3519
- support.citrix.com/article/CTX561482/citrix-adc-and-citrix-gate... support.citrix.com · CVE Record https://support.citrix.com/article/CTX561482/citrix-adc-and-citrix-ga...
- packetstormsecurity.com/files/173997/Citrix-ADC-NetScaler-Remote-Cod... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/173997/Citrix-ADC-NetScaler-Remo...
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the KEV Intelligence record.
Used in malware
CISA
Malware families have been linked to exploitation of this CVE.
Proof of concept available
GitHub
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2023-07-19 00:00 UTC |
| The Shadowserver | 2026-07-08 00:00 UTC |
| CVE | 2026-08-05 04:30 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner Artifacts
Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-3519.yaml | 01 Jun 2026 |
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/freebsd/http/citrix_formssso_target_rce.rb | 28 Apr 2025 |
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
9.8
Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
99.7%
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
Citrix NetScaler ADC and NetScaler Gateway - Remote Code Execution
nuclei · Created Unknown
Timeline
From disclosure to observed exploitation
-
KEV confirmed by CVE
Exploitation attested by an external source
-
KEV confirmed by The Shadowserver
Exploitation attested by an external source
-
Nuclei template available
Scanner coverage available
-
Metasploit module available
Exploit module available
-
Public PoC available
Public proof-of-concept code published
-
CVE published
Vulnerability disclosed publicly
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
First public exploitation report
Exploit observed in malware
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2023-3519
Free JSON includes basic KEV fields{
"cve_id": "CVE-2023-3519",
"confidence": "Confirmed",
"cvss_score": 9.8,
"cvss_estimated": false,
"epss_score": 0.99749,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.