CVE-2026-88779
Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
Citrix NetScaler
Vulnerability in NetScaler ADC and NetScaler Gateway. This issue affects ADC: before 14.1-73.41, before 13.1-64.28, before 14.1-73.41 FIPS, and before 13.1-37.282; Gateway: before 14.1-73.41 and before 13.1-64.28.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 4 October 2026. US federal agencies were required to remediate it by 7 October 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 0.6%, which is higher than 47.5% 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:N/I:N/A:H
Frequently asked questions
Is CVE-2026-88779 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2026-88779.
What does CVE-2026-88779 affect?
CVE-2026-88779 affects Citrix NetScaler. Vulnerability in NetScaler ADC and NetScaler Gateway. This issue affects ADC: before 14.1-73.41, before 13.1-64.28, before 14.1-73.41 FIPS, and before 13.1-37.282; Gateway: before 14.1-73.41 and before 13.1-64.28.
How severe is CVE-2026-88779?
CVE-2026-88779 is rated HIGH with a CVSS base score of 7.5. EPSS puts the probability of exploitation in the next 30 days at 0.6%, higher than 47.5% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 7 October 2026.
How should organisations respond to CVE-2026-88779?
Apply the vendor patch for Citrix NetScaler 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.