11:30am, 27 June 2025
TLP Rating:
CVE-2025-6543 affecting Citrix Netscaler products
CVE-2025-6543 (CVSS 9.2): A memory overflow defect that attackers could exploit for unintended control flow and denial of service. This vulnerability affects NetScaler products configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.
The NCSC is aware of open-source reporting of active exploitation of this vulnerability.
What's happening
Systems affected
The following supported versions of NetScaler ADC and NetScaler Gateway are affected by the vulnerabilities:
- NetScaler ADC and NetScaler Gateway 14.1 BEFORE 14.1-47.46
- NetScaler ADC and NetScaler Gateway 13.1 BEFORE 13.1-59.19
- NetScaler ADC 13.1-FIPS and NDcPP BEFORE 13.1-37.236-FIPS and NDcPP
- NetScaler ADC and NetScaler Gateway versions 12.1 and 13.0 (end-of-life)
Note: These are different versions to those previously listed in our advisory on CVE-2025-5777 and CVE-2025-5349.
What this means
Organisations who utilise affected NetScaler ADC and NetScaler Gateway versions could be vulnerable to the listed vulnerability.
What to look for
How to tell if you're at risk
If you are running a NetScaler ADC and NetScaler Gateway instance within the listed versions.
What to do
Prevention
Update to the latest version of NetScaler ADC and NetScaler Gateway.
More information
Vendor Advisory
CITRIX | Support External Link
If you require more information or further support, submit a report on our website.
Report an incident to CERT NZ External Link
For media enquiries, email our media desk at media@ncsc.govt.nz.
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