Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability
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 happened
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.
CISA lists it as exploited, added 09 Sep 2026.
Does it affect you
Names Citrix NetScaler ADC. Enter the product and version you run to place it against the affected range the vendor published.
What to do
- Follow the vendor advisory for the fixed release and any interim mitigation.
support.citrix.com - 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.
cisa.gov
CISA’s notes for this entry:
- support.citrix.com/external/article/CTX696939/netscaler-adc-and-netscaler-gateway-secu.html
- BOD 26-04: cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- Forensics Triage Requirements: cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- nvd.nist.gov/vuln/detail/CVE-2026-19490
Affected, as published to NVD
- citrix-adc
- Citrix NetScaler ADC: 13.1 up to the fix in 13.1-37.277
The record
- NVD status
- Analyzed
- Published
- 19 Aug 2026, last modified 07 Oct 2026 (NVD)
- Severity
- CVSS 3.1 base score 9.8, Critical — computed here from the vector; NVD states 9.8.
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness
- CWE-288 Authentication Bypass Using an Alternate Path or Channel (NVD; names by MITRE)
- Exploitation
- Listed in CISA’s Known Exploited Vulnerabilities catalogue since 09 Sep 2026; federal remediation due 12 Sep 2026. CISA entry
- Exploit probability
- EPSS 23.2%, 98th percentile — FIRST, scored 23 Oct 2026. FIRST EPSS
- Vendor
- Citrix · NetScaler (CISA)
References on the NVD record
- support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939Vendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-19490US Government Resource
Reporting that names this identifier
- Critical NetScaler Vulnerability Exploited in Attacks — SecurityWeek, 1 mo ago
- CISA Adds Four Known Exploited Vulnerabilities to Catalog — CISA, 2 mo ago
- Critical Citrix NetScaler auth bypass now leveraged in attacks — BleepingComputer, 2 mo ago
Sources
The verdict above is computed from the products and versions you entered and the affected ranges the vendor published to NVD. It does not inspect your environment, and this site never reports a product as unaffected: why.