Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability

Citrix NetScaler

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. Added to CISA KEV on 2026-09-09 (federal deadline 2026-09-12).

First seen: 9 Sept 2026
Last update: 9 Sept 2026, 12:00 UTC
Identifiers: CVE-2026-19490
Source: CISA KEV
On the menu as: VPN & firewalls

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability
Severity: high, exploited in the wild. Patch status: patched.
Affected: Citrix NetScaler
Ids: CVE-2026-19490

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. Added to CISA KEV on 2026-09-09 (federal deadline 2026-09-12).

## Steps
1. This touches infrastructure (vpn-edge). Look in terraform, ansible, cloud-init, Dockerfiles and docs for the product and version we run. If it isn't in the repo, say so and list what a human should check on the box.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-19490") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://nvd.nist.gov/vuln/detail/CVE-2026-19490 https://support.citrix.com/external/article/CTX696939/netscaler-adc-and-netscaler-gateway-secu.html
https://pwned.coffee/i/citrix-netscaler-authentication-bypass-using-an-alternat-cve-2026-19490

Sources

Totalone hot coffee