All vulnerabilities
CVE-2026-88771

Citrix NetScaler Improper Input Validation Vulnerability

Citrix NetScalerNetwork & edge
Open in ThreatlineRecord JSON
CVSS
9.5Critical
ExploitationExploited in the wildAdded to KEV 27 Sep 2026CISA KEV
Exploit odds (EPSS)4.72%Chance of exploitation activity in the next 30 days, higher than 91% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in14.1-73.37Also 13.1-64.23, 14.1-73.37 FIPS and 1 moreCVE List
Federal deadline30 Sep 2026Remediation due date for US federal agenciesCISA KEV
CISA required actionApply 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 KEV
Patching is not enoughCISA requires federal agencies to look for signs of compromise on affected systems, not only patch (forensic triage under BOD 26-04). Treat exposed systems as possibly compromised. CISA guidance

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 27 Sep 2026Exploit code publicMetasploit
  2. 27 Sep 2026Added to CISA KEVCISA KEV
  3. 27 Sep 2026, 16:02 UTCPublishedCVE List
  4. 28 Sep 2026, 10:55 UTCFirst reportwatchTowr Labs
  5. 29 Sep 2026, 14:00 UTCFirst reported exploitedGoogle Threat Intelligence

Public exploit code and templates 1

  • Exploit moduleCitrix NetScaler Unauthenticated Login Log Command Injection (CVE-2026-88771) 27 Sep 2026Metasploit

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Reports 3

3 outlets report exploitation. Reports are not confirmation; each links to its source.

Description

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

Text from CVE List

Affected versions 6

  • ADCaffected: all versions before 14.1-73.37CVE List
  • ADCaffected: all versions before 13.1-64.23CVE List
  • ADCaffected: all versions before 14.1-73.37 FIPSCVE List
  • ADCaffected: all versions before 13.1.37.279 FIPS and NDcPPCVE List
  • Gatewayaffected: all versions before 14.1-73.37CVE List
  • Gatewayaffected: all versions before 13.1-64.23CVE List

References 4