Critical severity · published Sep 27, 2026
CVE-2026-88776
Memory overflow vulnerability leading to unpredictable or erroneous behavior or Denial of Service
9.8
CVSS
0.7%
EPSS
No
On KEV
Description
Memory overflow vulnerability vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.
This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23 leading to unpredictable or erroneous behavior or Denial of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 54% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NA
NetScaler ADC · Citrix
before 14.1-73.37; before 13.1-64.23; before 14.1-73.37 FIPS; before 13.1.37.279 FIPS and NDcPP · source: vendor, NVD
GA
Gateway · Citrix NetScaler
before 14.1-73.37; before 13.1-64.23 · source: vendor
In the news
VulnerabilityCritical
Critical Zero-Day Vulnerabilities Exploited in Citrix NetScaler ADC, Gateway
CISA is amplifying Citrix’s disclosure of eight new vulnerabilities affecting Citrix NetScaler ADC and Citrix NetScaler Gateway products: CVE-2026-88771 , CVE-2026-88772 , CVE-2026-88773 , CVE-2026-88774 , CVE-2026-88775 , CVE-2026-88776 , CVE-2026-88777 , and CVE-2026-88778 .
CISA has added CVE-2026-88771 and CVE-2026-88772 to its Known Exploited Vulnerabilities (KEV) Catalog . Both are critical, zero-day vulnerabilities that can independently enable remote code execution. CISA has received reports and partner threat intelligence confirming that threat actors are actively exploiting these vulnerabilities globally.
Because updating Citrix NetScaler appliances can be complex and may require downtime, CISA is issuing this Alert to help organizations assess exposure, prioritize mitigation, and account for these vulnerabilities into their risk-management activities.
Given the potential consequences of successful exploitation and the fact that malicious actors are exploiting at least some of these vulnerabilities, CISA urges users and administrators to review Citrix’s advisories. If possible, users are encouraged to check for indication of compromise prior to patching. Citrix has made indicators of compromise available through NetScaler Console and published additional guidance in their recent publication, Security Bulletin for CVE-2026-88771 through CVE-2026-88778 , to support organizations in assessing potential compromise. Should your organization su...
Sep 27, 2026·CISA Advisories
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-88776
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-88776
support.citrix.com
https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096
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