Actively exploited in the wild
Citrix NetScaler Improper Input Validation Vulnerability
Citrix - NetScaler · Listed in the CISA KEV since 2026-09-27. This indicates confirmed attacks in production environments.
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.
CVE-2026-88771
CriticalCVSS 9.8KEVExploitation Probability (EPSS)
Elevated risk63th percentile - higher than 63% of all known CVEs
Summary
Improper input validation in Citrix NetScaler ADC and Gateway allows an unauthenticated attacker to execute arbitrary commands.
Risk Assessment
An unauthenticated attacker could execute arbitrary commands on the device, potentially leading to full system compromise.
Recommendation
Update Citrix NetScaler ADC and Gateway to patched versions (e.g., 14.1-73.37, 13.1-64.23).
Other vulnerabilities in Citrix NetScaler ADC
See all- CVE-2016-9028High
An unauthorized redirect vulnerability in Citrix NetScaler ADC before version 10.1 135.8, 10.5 61.11, 11.0 65.31/65.35F, and 11.1 47.14 allows a remote attacker to steal session cookies of a legitimate AAA user via manipulation of the Host header.
- CVE-2026-88777Critical
Memory overflow vulnerability in Citrix NetScaler ADC and Gateway leading to unpredictable or erroneous behavior or Denial of Service.
- CVE-2026-88776Critical
Memory overflow vulnerability in Citrix NetScaler ADC and Gateway leading to unpredictable or erroneous behavior or Denial of Service.
- CVE-2026-88775Critical
Memory overflow vulnerability in Citrix NetScaler ADC and Gateway leading to unpredictable or erroneous behavior or Denial of Service.
- CVE-2026-88773Critical
HTTP Request/Response Smuggling vulnerability in Citrix NetScaler ADC and Gateway due to inconsistent interpretation of HTTP requests.
- CVE-2026-88772HighActively exploited
Vulnerability in Citrix NetScaler ADC and Gateway leading to Remote Code Execution or Denial of Service.
- CVE-2026-88778High
Predictable exact value from previous values vulnerability in Citrix NetScaler ADC and Gateway.
- CVE-2026-88774High
Vulnerability in Citrix NetScaler ADC and Gateway leading to a feature policy bypass due to improper HTTP URL based expression usage.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS