Vulnerability · CVE-2026-88772

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

Published Sep 27, 2026 · corrected/updated Sep 28, 2026 · Citrix NetScaler ADC and NetScaler Gateway · evidence confidence very high

Overview On September 27, 2026, Citrix disclosed eight new vulnerabilities affecting NetScaler ADC and NetScaler Gateway, including two critical remote code execution (RCE) vulnerabilities: CVE-2026-88771 and CVE-2026-88772 . Both of these RCE vulnerabilities carry a critical CVSSv4 score of 9.5, and both have been confirmed as being actively exploited in the wild as zero-days prior to the vendor disclosure . CVE-2026-88771 affects vulnerable NetScaler deployments in their default configuration, with no additional product features required. The vendor has also indicated that the attack complex

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-88772 is a critical public vulnerability record for Citrix NetScaler ADC and NetScaler Gateway. CISA lists it as known exploited. Published remediation guidance: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Citrix NetScaler ADC and NetScaler Gateway is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: citrix/netscaler application delivery controller; citrix/netscaler gateway; Citrix NetScaler; Citrix NetScaler ADC and NetScaler Gateway. Published remediation guidance: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 9.5, EPSS 1.3%. CISA lists it as known exploited. Weakness classes: CWE-119. Sources contributing to this record: canada, cisa_kev, cve_org, epss. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

Exploitation evidence
Confirmed in CISA KEV since Sep 27, 2026. Listed in CISA KEV and VulnCheck KEV.
Patch and remediation
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. CISA due date Sep 30, 2026.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

Sep 27, 2026 · Catalog
Detected
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 Remote Code Execution or Denial of Service
Sep 27, 2026 · CISA KEV
Known exploited
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating
Sep 28, 2026 · Catalog
Updated
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 Remote Code Execution or Denial of Service
Sep 30, 2026 · CISA KEV
Remediation due
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating

Affected

cpe citrix/netscaler application delivery controllerversion unspecified
cpe citrix/netscaler gatewayversion unspecified
vendor Citrix NetScalerversion unspecified
vendor Citrix NetScaler ADC and NetScaler Gatewayversion unspecified

Sources

Canadian Centre for Cyber SecurityGovernment advisoryCVE-2026-88772
Number: AL26-024 Date: September 27, 2026 Update: October 9, 2026 Audience This Alert is intended for IT professionals and managers. Purpose An Alert is used to raise awareness of a recently identified cyber threat that may impact cyber information assets, and to provide addition
cyber.gc.ca
CISA KEVConfirmed exploitationCVE-2026-88772
Citrix NetScaler ADC and NetScaler Gateway contain an improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for remote code execution or denial of service
cisa.gov
CVE.orgVulnerability recordCVE-2026-88772
Official CVE identifier
cve.org
FIRST EPSSExploitation probabilityCVE-2026-88772
30-day exploitation probability 1.3%
first.org
Google Threat IntelligenceThreat researchCVE-2026-88772
Research mention from Google Threat Intelligence. Not confirmation of exploitation.
cloud.google.com
NIST NVDVulnerability recordCVE-2026-88772
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 Remote Code Execution or D
nvd.nist.gov
Rapid7 Vulnerability DatabaseResearchCVE-2026-88772
Overview On September 27, 2026, Citrix disclosed eight new vulnerabilities affecting NetScaler ADC and NetScaler Gateway, including two critical remote code execution (RCE) vulnerabilities: CVE-2026-88771 and CVE-2026-88772 . Both of these RCE vulnerabilities carry a critical CVSSv4 score of 9.5, and both have been confirmed as being actively exploited in the wild as zero-days prior to the vendor
rapid7.com
Palo Alto Unit 42Threat researchCVE-2026-88772
Research mention from Palo Alto Unit 42. Not confirmation of exploitation.
unit42.paloaltonetworks.com
VulnCheck KEVConfirmed exploitationCVE-2026-88772
Citrix NetScaler ADC and NetScaler Gateway contain an improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for remote code execution or denial of service
vulncheck.com