CVE-2026-88771

Published Sep 27, 2026

Last updated a month ago

Exploit known CVSS critical 9.5

VDI

SAP

Cloud

Zero-day

System

SSL

Dns

VPN

Mobile device

Tls

Citrix NetScaler ADC

Citrix NetScaler Gateway

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-88771 is identified as an improper input validation vulnerability affecting Citrix NetScaler ADC and NetScaler Gateway products. This flaw enables an unauthenticated attacker to execute arbitrary commands on affected systems. The vulnerability impacts all deployments of NetScaler ADC and NetScaler Gateway, and no specific additional features are required for it to be exploitable. Citrix confirmed that this vulnerability, alongside CVE-2026-88772, has been actively exploited in the wild on unmitigated NetScaler deployments. The company released security updates to address these issues, which were attacked before a public fix was available. NetScaler ADC and NetScaler Gateway appliances are commonly deployed at the edge of enterprise networks, handling functions such as VPN, remote access, load balancing, and user authentication.

Description: Improper input validation 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 an unauthenticated attacker to execute arbitrary commands.
Source: 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
NVD status: Analyzed
Products: netscaler_application_delivery_controller, netscaler_gateway

Risk scores

CVSS 4.0

Type: Secondary
Base score: 9.5
Impact score: -
Exploitability score: -
Vector string: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity: CRITICAL

CVSS 3.1

Type: Primary
Base score: 9.8
Impact score: 5.9
Exploitability score: 3.9
Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: CRITICAL

Known exploits

Data from CISA

Vulnerability name: Citrix NetScaler Improper Input Validation Vulnerability
Exploit added on: Sep 27, 2026
Exploit action due: Sep 30, 2026
Required action: 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.

Weaknesses

50a63c94-1ea7-4568-8c11-eb79e7c5a2b5: CWE-20

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*",
            "matchCriteriaId": "6BC2D462-9ABE-4024-8E46-8D265C0B19FB",
            "versionEndExcluding": "13.1-64.23",
            "versionStartIncluding": "13.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*",
            "matchCriteriaId": "2DB314FE-3886-4ABD-A820-B8A70EBB23A6",
            "versionEndExcluding": "13.1.37.279",
            "versionStartIncluding": "13.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:*",
            "matchCriteriaId": "FCFFA1B3-87CE-4CC8-990E-D3CE0B55CD45",
            "versionEndExcluding": "13.1.37.279",
            "versionStartIncluding": "13.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*",
            "matchCriteriaId": "1CA9588A-E3EB-44FC-9515-6EB89BB8C1D6",
            "versionEndExcluding": "14.1-73.37",
            "versionStartIncluding": "14.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*",
            "matchCriteriaId": "046FF602-D956-4961-89BF-2041A3590004",
            "versionEndIncluding": "14.1-73.37",
            "versionStartIncluding": "14.1-66.68",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "3286D2C3-EA7E-4D9C-95DE-05D462DC8B1B",
            "versionEndExcluding": "13.1-64.23",
            "versionStartIncluding": "13.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "C77243A7-1FDB-4557-88BE-EDF3BAA56A81",
            "versionEndExcluding": "14.1-73.37",
            "versionStartIncluding": "14.1",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.