Vulnary
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Critical· 9.8actively exploitedofficial fix available

CVE-2023-3519

This vulnerability allows attackers to run arbitrary code on Citrix NetScaler devices without authentication. It can be exploited remotely over the network. The flaw is critical and has been actively exploited.

publishedJul 19, 2023
last modifiedAug 5, 2026
sourcesNVD · CISA-KEV
severity · cvss
9.8
critical · how bad it is
exploitation · epss
100%
100th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Sep 4, 2026

An official fix is available, so this entry is kept for 30 days and then removed automatically.

01

Who is affected

Citrix NetScaler Application Delivery Controller and Citrix NetScaler Gateway devices.

02

Real-world impact

An attacker could take full control of the affected device, compromising any services it manages, and potentially access sensitive data or disrupt network traffic.

03

Why this severity

The CVSS score of 9.8 reflects that the flaw can be exploited remotely with no authentication or user interaction, giving attackers complete control over the system.

04

What to do about it

official fix available
recommended steps
  1. 01Follow the vendor’s mitigation guidance for Citrix NetScaler Application Delivery Controller and Gateway.

CISA KEV required action

05

Timeline

  1. Jul 19, 2023 · Jul 19, 2023
    Confirmed exploited (CISA KEV)
    CISA added it to the Known Exploited Vulnerabilities catalog — attackers are using it in the wild.
  2. Jul 19, 2023 · Jul 19, 2023
    Published
    Disclosed and added to the National Vulnerability Database.
  3. Aug 9, 2023 · Aug 9, 2023
    CISA remediation deadline
    Federal agencies are required to remediate by this date.
  4. Aug 5, 2026 · 1d ago
    Advisory updated
    The NVD record was last revised.
  5. Aug 5, 2026 · 1d ago
    Official fix available
    A vendor patch or mitigation now exists — see the remediation steps above.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Privileges requiredNone
User interactionNone needed
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
07

References & advisories

NVD advisory ↗CISA KEV catalog ↗Search advisories ↗
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →