CVE-2026-19490
Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 12 September 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 4.0
- 9.3 CRITICALCVSS:4.0/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/M
- EPSS
- 5.60% probability · 92th percentile
- CISA KEV
- Listed 9 September 2026 · due 12 September 2026
- Weakness
- CWE-288
- Affected
- citrix/netscaler application delivery controller · citrix/netscaler gateway
- Source
- 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
CISA notes
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. 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
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.