CRITICAL · CVSS 9.8 CISA Known Exploited Vulnerability

CVE-2026-8452

Citrix NetScaler ADC and NetScaler Gateway Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability

Citrix NetScaler ADC and NetScaler Gateway

Memory overflow vulnerability NetScaler ADC and NetScaler Gateway leading to unpredictable or erroneous behavior and Denial of Service if the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server

CVSS
9.8
CRITICAL
EPSS
1.6%
30-day exploitation
Ransomware groups
0
recorded exploiting
Published
30 Jun 2026
CWE-119

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 26 August 2026. US federal agencies were required to remediate it by 29 August 2026.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 1.6%, which is higher than 74.8% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Frequently asked questions

Is CVE-2026-8452 being exploited by ransomware groups?

No ransomware group in this database is currently recorded as exploiting CVE-2026-8452.

What does CVE-2026-8452 affect?

CVE-2026-8452 affects Citrix NetScaler ADC and NetScaler Gateway. Memory overflow vulnerability NetScaler ADC and NetScaler Gateway leading to unpredictable or erroneous behavior and Denial of Service if the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server

How severe is CVE-2026-8452?

CVE-2026-8452 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 1.6%, higher than 74.8% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 29 August 2026.

How should organisations respond to CVE-2026-8452?

Apply the vendor patch for Citrix NetScaler ADC and NetScaler Gateway as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.