CVEvulnerability

CVE-2026-88771

9.5 CRITICAL Known exploited Published 2026-09-27 Modified 2026-09-29 Official page ↗

CISA Known Exploited Vulnerability

Citrix NetScaler Improper Input Validation Vulnerability — Citrix NetScaler

Citrix NetScaler ADC and NetScaler Gateway contain an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.

Added to KEV
2026-09-27
Remediation due
2026-09-30
Ransomware use
Unknown
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.
Notes
Running the provided IOCs in the NetScaler console may help identify indicators of exploitation. Customers must conduct forensic triage as directed by BOD 26‑04 and follow Citrix’s published guidance for mitigations. For more information, please see: https://community.citrix.com/techzone-blogs/110_security-updates/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve-2026-88771-through-cve-2026-88778 ; https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096 ; https://support.citrix.com/external/article/CTX694799/steps-to-take-if-netscaler-adc-is-suspec.html ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-88772
Status
Analyzed
Published
2026-09-27
Last modified
2026-09-29
Assigner
50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
CVSS 4.0 (50a63c94-1ea7-4568-8c11-eb79e7c5a2b5)
9.5 CRITICAL — 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
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-20

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.

Affected configurations

• citrix netscaler application delivery controller (>= 13.1 < 13.1-64.23) • citrix netscaler application delivery controller (>= 13.1 < 13.1.37.279) • citrix netscaler application delivery controller (>= 14.1 < 14.1-73.37) • citrix netscaler application delivery controller (>= 14.1-66.68 <= 14.1-73.37) • citrix netscaler gateway (>= 13.1 < 13.1-64.23) • citrix netscaler gateway (>= 14.1 < 14.1-73.37)

Related

Weakness · CWE (1)

  • CWE-20 Improper Input Validation weakness

References