# CVE-2026-88771: Citrix NetScaler Improper Input Validation

> Unauthenticated attackers can execute arbitrary commands on Citrix NetScaler ADC and Gateway due to improper input validation.

- **Severity:** Critical 9.5 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Yes, since 27 Sep 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Sep 2026
- **Updated:** 29 Sep 2026
- **Also known as:** GHSA-mx58-p288-86qp

## What is CVE-2026-88771?

CVE-2026-88771 is a critical command injection vulnerability in Citrix NetScaler ADC, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.

This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23 leading to an unauthenticated attacker to execute arbitrary commands.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-88771?

It affects 2 products.


Products: Citrix NetScaler ADC, Citrix Netscaler Gateway.

## How do I fix CVE-2026-88771?

No fix has been published for CVE-2026-88771 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 30 Sep 2026.

## Is CVE-2026-88771 being exploited?

Yes. Attackers have exploited CVE-2026-88771 in the wild since at least 27 Sep 2026.

Public exploit code:

- https://github.com/watchtowrlabs/watchTowr-vs-Citrix-Netscaler-CVE-2026-88771 (github_poc): https://github.com/watchtowrlabs/watchTowr-vs-Citrix-Netscaler-CVE-2026-88771
- Am I fixed? Was I hacked? Read-only checker for Citrix NetScaler CTX697096 (CVE-2026-88771–88778), CTX697174, CTX697191 (SAML RCE) and CTX697263 php2shell (fixed in 14.1-73.49 / 13.1-64.32): build, CVE preconditions, SAML, mgmt exposure, MFA, upgrade risks + IoC sweep with every public IoC (webshells, implants, 133 attacker IPs). (github_poc): https://github.com/ThomasPoppelgaard/netscaler-ctx697096-checker
- Tooling related to CVE-2026-88771 and CVE-2026-88772 (github_poc): https://github.com/technion/netscaler_scanner
- https://github.com/craigsblackie/cve-2026-88771-netscaler (github_poc): https://github.com/craigsblackie/cve-2026-88771-netscaler
- Defensive security checker for Citrix NetScaler ADC & Gateway — CVE-2026-88771 through CVE-2026-88778 (github_poc): https://github.com/grupooruss/netscaler-defensive-checker
- Citrix NetScaler Unauthenticated Login Log Command Injection (CVE-2026-88771) (metasploit)

## Other vulnerabilities in Citrix 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-2026-88772](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-2026-19490](https://insights.sbomify.com/CVE-2026-19490/): Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel (critical 9.3, 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-2026-88771 and fix it if it is affected.

What it is: CVE-2026-88771 is a critical command injection vulnerability in Citrix NetScaler ADC, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-88771 in the wild since at least 27 Sep 2026.

Affected product: Citrix 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-2026-88771/ (Markdown: https://insights.sbomify.com/CVE-2026-88771/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88771
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88771
- OSV: https://osv.dev/vulnerability/CVE-2026-88771

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88771/
Summaries are generated and may contain mistakes; the official description above is the record.