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Known Exploited Vulnerability
9.8
CRITICAL CVSS 3.1
CVE-2026-19490
Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability - [Actively Exploited]
Overview
Description

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.

Details
INFO

Published Date :

Aug. 19, 2026, 1:17 p.m.

Last Modified :

Sept. 10, 2026, 12:48 p.m.

Remotely Exploit :

Yes !

Source :

50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

Citrix NetScaler ADC and NetScaler Gateway contain an authentication-bypass vulnerability involving an alternate path or channel. When the NetScaler appliance is configured as an AAA virtual server or as a Gateway (SSL VPN, ICA Proxy, CVPN, or RDP Proxy), an unauthenticated remote threat actor may be able to bypass authentication.

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.

Known Ransomware Campaign Use:

Unknown

Notes :

https://support.citrix.com/external/article/CTX696939/netscaler-adc-and-netscaler-gateway-secu.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-2026-19490

Impact
Affected Products

The following products are affected by CVE-2026-19490 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Citrix netscaler_application_delivery_controller
2 Citrix netscaler_gateway
: Total Affected Vendor : 1 | Products : 2
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
CVSS 4.0 CRITICAL 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
Solution
Update NetScaler ADC and Gateway software to the latest versions.
  • Update NetScaler ADC to version 14.1 build 73.32 or later.
  • Update NetScaler ADC to version 13.1 build 63.21 or later.
  • Update NetScaler Gateway to version 14.1 build 73.32 or later.
  • Update NetScaler Gateway to version 13.1 build 63.21 or later.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-19490.

URL Resource
https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939 Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-19490 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-19490 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-19490 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-19490 vulnerability anywhere in the article.

  • TheCyberThrone
Citrix NetScaler Zero-Days Exploited in the Wild: CISA Adds Them to KEV

Executive SummaryCitrix has confirmed that two NetScaler ADC and NetScaler Gateway zero-day vulnerabilities — CVE-2026-88771 and CVE-2026-88772 — are being exploited in the wild.Both are rated CVSS 9. ... Read more

Published Date: Sep 28, 2026 (1 day, 10 hours ago)
  • The Hacker News
Warning: Two Unpatched Citrix NetScaler RCE Zero-Days Under Active Exploitation

Two new unpatched zero-day vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway appliances that allow remote code execution are being actively exploited in the wild, security firm watchTowr s ... Read more

Published Date: Sep 27, 2026 (2 days, 4 hours ago)
  • The Hacker News
CISA Flags Exploited Cisco, Citrix, Fortinet Flaws, Sets Sept. 12 Federal Patch Deadline

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Wednesday added three flaws, each impacting Cisco, Citrix, and Fortinet, to its Known Exploited Vulnerabilities (KEV) catalog, requi ... Read more

Published Date: Sep 10, 2026 (2 weeks, 5 days ago)
  • TheCyberThrone
CISA KEV Update – 8 Vulnerabilities Added in Two Days

CISA’s Known Exploited Vulnerabilities (KEV) Catalog saw a significant two-day update on September 8 and September 9, 2026, with eight vulnerabilities added based on evidence of active exploitation.CI ... Read more

Published Date: Sep 10, 2026 (2 weeks, 5 days ago)
  • security.nl
Kritiek beveiligingslek in Citrix NetScaler actief misbruikt bij aanvallen

Aanvallers maken actief misbruik van een kritieke kwetsbaarheid in Citrix NetScaler, zo waarschuwen het Belgische Centrum voor Cybersecurity (CCB) en cybersecuritybedrijf Previdian. Citrix kwam op 19 ... Read more

Published Date: Sep 07, 2026 (3 weeks, 1 day ago)
  • The Cyber Express
The Cyber Express Weekly Roundup: Claude Session Hijacking, PaperCut Exploits, and Enterprise Cyberattacks

This weekly roundup highlights a range of cybersecurity developments affecting artificial intelligence platforms, enterprise software, healthcare organizations, social media accounts, and internet-fac ... Read more

Published Date: Sep 04, 2026 (3 weeks, 4 days ago)
  • The Cyber Express
Two Citrix NetScaler Flaws Put Enterprise Edge Devices at Risk

Two Citrix NetScaler vulnerabilities affecting Citrix NetScaler Application Delivery Controller (ADC) and Citrix NetScaler Gateway products have prompted a patching warning for Australian organisation ... Read more

Published Date: Sep 04, 2026 (3 weeks, 4 days ago)
  • TheCyberThrone
Critical NetScaler Security Update Patching Two Vulnerabilities

Cloud Software Group has released security updates for NetScaler ADC and NetScaler Gateway addressing two vulnerabilities, including a critical authentication-bypass flaw rated CVSS 9.3.The more serio ... Read more

Published Date: Aug 21, 2026 (1 month, 1 week ago)
  • security.nl
Kritiek Citrix NetScaler-lek kan aanvaller toegang tot systeem geven

Een kritieke kwetsbaarheid in Citrix NetScaler ADC en Citrix NetScaler Gateway kan ongeauthenticeerde aanvallers toegang tot het systeem geven. Er zijn beveiligingsupdates uitgebracht om het probleem ... Read more

Published Date: Aug 20, 2026 (1 month, 1 week ago)
  • The Hacker News
Critical NetScaler Flaw Can Bypass Authentication on Certain Gateway and AAA Servers

Citrix has released updates to address two security flaws impacting NetScaler ADC and NetScaler Gateway deployments, including a critical-severity authentication bypass vulnerability. According to the ... Read more

Published Date: Aug 20, 2026 (1 month, 1 week ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-19490 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Sep. 10, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CPE Configuration OR *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:* versions from (including) 13.1 up to (excluding) 13.1-63.21 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:* versions from (including) 14.1 up to (excluding) 14.1-73.32 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:* versions from (including) 14.1-66.68 up to (including) 14.1-73.32 *cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:* versions from (including) 13.1 up to (excluding) 13.1-63.21 *cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:* versions from (including) 14.1 up to (excluding) 14.1-73.32 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:* versions from (including) 13.1 up to (excluding) 13.1-37.277 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:* versions from (including) 13.1 up to (excluding) 13.1-37.277
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-19490 Types: US Government Resource
    Added Reference Type NetScaler: https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939 Types: Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 10, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-19490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-09T19:50:05.742072Z'} {'id': 'CVE-2026-19490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-19T00:00:00+00:00'}
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Sep. 09, 2026

    Action Type Old Value New Value
    Added Date Added 2026-09-09
    Added Due Date 2026-09-09
    Added Required Action 2026-09-09
    Added Vulnerability Name 2026-09-09
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 09, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-19490
    Changed SSVC {'id': 'CVE-2026-19490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-20T03:56:10.740519Z'} {'id': 'CVE-2026-19490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-09T19:50:05.742072Z'}
  • CVE Modified by 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5

    Sep. 09, 2026

    Action Type Old Value New Value
    Added Reference https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939
    Removed Reference https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 20, 2026

    Action Type Old Value New Value
    Added CWE CWE-288
    Changed SSVC {'id': 'CVE-2026-19490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-19T00:00:00+00:00'} {'id': 'CVE-2026-19490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-20T03:56:10.740519Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 20, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-19490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-19T00:00:00+00:00'}
  • New CVE Received by 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5

    Aug. 19, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'NetScaler', 'product': 'ADC', 'versions': [{'status': 'affected', 'version': '14.1', 'versionType': 'patch', 'lessThanOrEqual': '73.32'}, {'status': 'affected', 'version': '13.1', 'versionType': 'patch', 'lessThanOrEqual': '63.21'}], 'defaultStatus': 'unaffected'}, {'vendor': 'NetScaler', 'product': 'Gateway', 'versions': [{'status': 'affected', 'version': '14.1', 'versionType': 'patch', 'lessThanOrEqual': '73.32'}, {'status': 'affected', 'version': '13.1', 'versionType': 'patch', 'lessThanOrEqual': '63.21'}], 'defaultStatus': 'unaffected'}]
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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
    Added Reference https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 9.3
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact