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CVE-2026-19490

Citrix — Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability

Citrix · CWE-288 · in CISA KEV since 2026-09-09

CISA federal deadline · Overdue by 43 daysCISA KEVActively Exploited
75

EVRS 75 of 100 Urgent

Patch This Cycle

Rank 882 of 2,956 tracked

Raised to the floor for a confirmed exploited vulnerability.

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Why it scores 75

Evidence available: 6 of 7 signals

Listed in the CISA KEV catalog, and an EPSS probability of 0.232.

  • CISA KEVApplied
  • RansomwareDid not apply
  • Vendor exploitationDid not apply
  • EPSSApplied
  • Microsoft Exploitability IndexNot applicable
  • Pre-patch disclosureNo data
  • KEV recencyApplied
  • CVSSApplied

The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data

Fix

Patch or fixed version identified

CISA required action

Fixed in

netscaler application delivery controller: update to 13.1-37.277 or later | netscaler application delivery controller: update to 13.1-63.21 or later | netscaler application delivery controller: update to 14.1-73.32 or later | netscaler application delivery controller: update to a version newer than 14.1-73.32 | netscaler gateway: update to 13.1-63.21 or later | netscaler gateway: update to 14.1-73.32 or later

Affected versions

  • netscaler application delivery controller>= 13.1 < 13.1-37.277>= 13.1 < 13.1-63.21>= 14.1 < 14.1-73.32>= 14.1-66.68 <= 14.1-73.32
  • netscaler gateway>= 13.1 < 13.1-63.21>= 14.1 < 14.1-73.32

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.

Fixed versions from NVD.

Evidence

Each value with its source
MeasureValueSource
CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. 9.3 NVD
FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. 0.232 (97.8th pctl) FIRST EPSS
Actively exploitedWhether a source of record has confirmed attacks using it in the wild. Confirmed CISA KEV
Ransomware campaign useWhether CISA has seen ransomware operators use it. Unknown or none CISA KEV
CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. 2026-09-12 · CISA federal deadline · Overdue by 43 days CISA KEV
Public exploit moduleA module existing is not the same as active exploitation. None known Metasploit
EUVD cross-referenceENISA's record: CVSS 9.3 (v4.0), assigned by NetScaler. Listed ENISA EUVD

Description

NVD

Vulnerability in NetScaler ADC and NetScaler Gateway. This issue affects ADC: from 14.1 through 73.32 and from 13.1 through 63.21; Gateway: from 14.1 through 73.32 and from 13.1 through 63.21.

What CISA says to do