NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2026-3055 and CVE-2026-4368

by | März 23, 2026 | ALARM, ctx_adc

Attention! Please note the following regarding to this update:

Customers who already have transitioned to Netscaler LAS can upgrade without any special remarks. If you have not yet changed the Licensing mode, please check the requirements for LAS prior to the update!

Upgrading without proper LAS activation can lead to licensing issues. While these can be resolved by downloading a new file-based license, this workaround is only available until April 15, 2026.

Severity – Critical

Description of Problem

Vulnerabilities have been discovered in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway). Refer below for further details.

Affected Versions:

The following supported versions of NetScaler ADC and NetScaler Gateway are affected by the vulnerabilities: 

CVE-2026-3055:

  • NetScaler ADC and NetScaler Gateway 14.1 BEFORE 14.1-66.59
  • NetScaler ADC and NetScaler Gateway 13.1 BEFORE 13.1-62.23
  • NetScaler ADC FIPS and NDcPP BEFORE 13.1-37.262


CVE-2026-4368:

  • NetScaler ADC and NetScaler Gateway  14.1-66.54


Note: This bulletin only applies to customer-managed NetScaler ADC and NetScaler Gateway. Cloud Software Group upgrades Citrix-managed cloud services and Citrix-managed Adaptive Authentication with the necessary software updates.

Details

NetScaler ADC and NetScaler Gateway are affected by the vulnerabilities mentioned below:

CVE-IDDescriptionPre-conditionsCWECVSS v4.0
CVE-2026-3055Insufficient input validation leading to memory overreadCitrix ADC or Citrix Gateway must be configured as a SAML IDPCWE-125: Out-of-bounds ReadCVSS v4.0 Base Score: 9.3(CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L)
CVE-2026-4368Race Condition leading to User Session MixupAppliance must be configured as:Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy)           OR AAA virtual serverCWE-362: Race ConditionCVSS v4.0 Base Score: 7.7(CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)

What Customers Should Do

CVE 2026-3055 was identified internally through our ongoing security reviews and broader efforts to strengthen the security of the product. 

Cloud Software Group strongly urges affected customers of NetScaler ADC and NetScaler Gateway to install the relevant updated versions as soon as possible.

  • NetScaler ADC and NetScaler Gateway 14.1-66.59 and later releases
  • NetScaler ADC and NetScaler Gateway 13.1-62.23 and later releases of 13.1
  • NetScaler ADC 13.1-FIPS and 13.1-NDcPP 13.1.37.262 and later releases of 13.1-FIPS and 13.1-NDcPP

Note: Customers are recommended to upgrade their appliances to one of the supported versions that address the vulnerabilities. 

CVE-2026-3055 : 

Customers can determine if they have an appliance configured as a SAML IDP Profile by inspecting their NetScaler Configuration for the specified string:

  • add authentication samlIdPProfile .*

CVE-2026-4368

Customers can determine if they have an appliance configured as one of the following by inspecting their NetScaler Configuration for the specified strings

  • An Auth Server (AAA Vserver):
    • add authentication vserver .*
  • A Gateway (VPN Vserver,  ICA Proxy, CVPN, RDP Proxy) :
    • add vpn vserver .*

Source: https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696300&articleTitle=NetScaler_ADC_and_NetScaler_Gateway_Security_Bulletin_for_CVE_2026_3055_and_CVE_2026_4368&