# CVE-2026-19490: Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel

> Attackers can bypass authentication in NetScaler ADC and Gateway, potentially gaining unauthorized access to the network infrastructure.

- **Severity:** Critical 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`)
- **Exploited in the wild:** Yes, since 9 Sep 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Aug 2026
- **Updated:** 7 Oct 2026
- **Also known as:** GHSA-7c6h-rhhv-wm8r

## What is CVE-2026-19490?

CVE-2026-19490 is a critical authentication bypass vulnerability in NetScaler ADC, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2026-19490?

It affects 2 products.


Products: Citrix NetScaler ADC, Citrix Netscaler Gateway.

## How do I fix CVE-2026-19490?

No fix has been published for CVE-2026-19490 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 12 Sep 2026.

## Is CVE-2026-19490 being exploited?

Yes. Attackers have exploited CVE-2026-19490 in the wild since at least 9 Sep 2026.

Public exploit code:

- NetScaler ADC/Gateway SAML unsigned-assertion bypass via HTTP-Redirect binding (CTX696939) - root cause analysis + PoC (github_poc): https://github.com/TarPeg007/CVE-2026-19490
- Safely detect Citrix NetScaler SAML auth bypass CVE-2026-19490 (github_poc): https://github.com/BishopFox/CVE-2026-19490-check
- Offline NetScaler ADC / Gateway evidence checker for CVE-2026-19490. Reported firmware and configuration evidence. Standalone Python; JSON/CSV/HTML reports; no exploit payloads. (github_poc): https://github.com/CompleteTech-Security/netscaler-cve-2026-19490-check

## Other vulnerabilities in NetScaler ADC

- [CVE-2023-3519](https://insights.sbomify.com/CVE-2023-3519/): Citrix NetScaler ADC and NetScaler Gateway Code Injection (critical 9.8, exploited in the wild)
- [CVE-2026-88771](https://insights.sbomify.com/CVE-2026-88771/): Citrix NetScaler Improper Input Validation (critical 9.5, exploited in the wild)
- [CVE-2026-88772](https://insights.sbomify.com/CVE-2026-88772/): Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer (critical 9.5, exploited in the wild)
- [CVE-2023-4966](https://insights.sbomify.com/CVE-2023-4966/): Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow (critical 9.4, exploited in the wild)
- [CVE-2026-3055](https://insights.sbomify.com/CVE-2026-3055/): Citrix NetScaler Out-of-Bounds Read (critical 9.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-19490 and fix it if it is affected.

What it is: CVE-2026-19490 is a critical authentication bypass vulnerability in NetScaler ADC, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-19490 in the wild since at least 9 Sep 2026.

Affected product: NetScaler ADC. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-19490/ (Markdown: https://insights.sbomify.com/CVE-2026-19490/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-19490
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-19490
- OSV: https://osv.dev/vulnerability/CVE-2026-19490

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-19490/
Summaries are generated and may contain mistakes; the official description above is the record.