# CVE-2026-88771 — Citrix NetScaler ADC

> As of 2026-09-27, CVE-2026-88771 is a Critical-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in Citrix NetScaler ADC, CVSS v4.0 9.5. Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-88771, most recently “Citrix Patches Two Actively Exploited NetScaler Zero-Days (CVE-2026-88771, CVE-2026-88772)”.

**Last updated:** 2026-09-27

## What is CVE-2026-88771?

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.

The record classifies CVE-2026-88771 under weakness class [CWE-20](https://cwe.mitre.org/data/definitions/20.html). 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 1 day ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 9.5 — Critical (derived from score) (`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`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-27

## Is CVE-2026-88771 being exploited?

No public exploitation evidence for CVE-2026-88771 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-09-27. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- **Citrix NetScaler**: ADC, Gateway

## How to fix CVE-2026-88771

No vendor patch reference has been recorded for CVE-2026-88771 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-88771

2 tracked threats in the Threadlinqs corpus reference CVE-2026-88771, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Citrix Patches Two Actively Exploited NetScaler Zero-Days (CVE-2026-88771, CVE-2026-88772)](https://intel.threadlinqs.com/threat/TL-2026-2703) — CRITICAL · 2026-09-27
- [CISA Adds Two Citrix NetScaler Vulnerabilities (CVE-2026-88771, CVE-2026-88772) to KEV Catalog](https://intel.threadlinqs.com/threat/TL-2026-2711) — CRITICAL · 2026-09-27

## Sources

Enriched from CVE.org. Last verified by Threadlinqs on 2026-09-27.

**Other references**

- [support.citrix.com](https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-88771
Full detection coverage and IOCs for threats exploiting CVE-2026-88771 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp