What is CVE-2023-3519?
Unauthenticated remote code execution
The record classifies CVE-2023-3519 under weakness class CWE-94. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 4 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 1198 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 99.7% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
- CISA KEV
- Listed since 2023-07-19, federal remediation deadline 2023-08-09 — used in known ransomware campaigns
- Threadlinqs priority
- 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
- Published
- 2023-07-19, last modified 2026-08-05
Is CVE-2023-3519 being exploited?
CISA added CVE-2023-3519 to the Known Exploited Vulnerabilities catalog on 2023-07-19, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2023-08-09 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. Weaponised exploit code for CVE-2023-3519 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2023/CVE-2023-3519.yaml). It currently carries a trending score of 55 in the Threadlinqs vulnerability feed.
- BishopFox/CVE-2023-3519 (github)
- securekomodo/citrixInspector (github)
- mandiant/citrix-ioc-scanner-cve-2023-3519 (github)
- telekom-security/cve-2023-3519-citrix-scanner (github)
- mr-r3b00t/CVE-2023-3519 (github)
- SalehLardhi/CVE-2023-3519 (github)
- Chocapikk/CVE-2023-3519 (github)
- dhammerg/CVE-2023-3519 (github)
Affected products and versions
- Citrix: Netscaler Application Delivery Controller, Netscaler Gateway
Showing 2 of 4 recorded product entries.
How to fix CVE-2023-3519
The record marks a vendor fix as available for CVE-2023-3519. Patch reference: https://support.citrix.com/article/CTX561482. Vendor advisory: https://support.citrix.com/article/CTX561482/citrix-adc-and-citrix-gateway-security-bulletin-for-cve20233519-cve20233466-cve20233467. Because CVE-2023-3519 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2023-08-09. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2023-3519
5 tracked threats in the Threadlinqs corpus reference CVE-2023-3519, either in the campaign’s CVE list or as an indicator on the campaign record.
- INC Ransomware: Evolution into a Top-Tier RaaS Operation (Rust Windows/ESXi payloads, edge-device exploitation CVE-2023-3519/CVE-2023-48788/CVE-2024-57727/CVE-2025-5777, modified Veeam credential dumper) — HIGH · 2026-10-22
- 2026 Ransomware Surge Targeting US Organizations: Identity-First Compromise, BYOVD, and Living-Off-the-Cloud Exfiltration (Qilin, Akira, Clop, INC Ransom, Play, DragonForce, Sinobi) — HIGH · 2026-08-23
- FortiBleed Credential-Harvesting Campaign Against 430,000 FortiGate Firewalls Feeds INC Ransom and Lynx Ransomware Operations — CRITICAL · 2026-07-02
- INC Ransom Affiliate Network Targeting Pacific Critical Infrastructure (AU/NZ/Tonga Joint Advisory) — CRITICAL · 2026-03-09
- Citrix NetScaler Mass Reconnaissance Campaign via Residential Proxies — HIGH · 2026-02-03
Sources
Enriched from CVE.org, FIRST EPSS, CISA KEV, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on .