# CVE-2026-19489 — NetScaler ADC

> As of 2026-08-20, CVE-2026-19489 is a High-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in NetScaler ADC, CVSS v4.0 8.8. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-19489, most recently “CVE-2026-19490 — Critical Authentication Bypass in Citrix NetScaler ADC and Gateway (CVSS 9.3) with Accompanying CVE-2026-19489 Memory Overflow (CVSS 8.8)”.

**Last updated:** 2026-08-20

## What is CVE-2026-19489?

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.

The record classifies CVE-2026-19489 under weakness class [CWE-120](https://intel.threadlinqs.com/cwe/CWE-120). 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 47 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 8.8 — High (derived from score) (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:L`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-19, last modified 2026-08-20

## Is CVE-2026-19489 being exploited?

No public exploitation evidence for CVE-2026-19489 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-08-20. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- [NetScaler](https://intel.threadlinqs.com/vendors/netscaler): ADC, Gateway

## How to fix CVE-2026-19489

No vendor patch reference has been recorded for CVE-2026-19489 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-2026-19489

1 tracked threat in the Threadlinqs corpus references CVE-2026-19489, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2026-19490 — Critical Authentication Bypass in Citrix NetScaler ADC and Gateway (CVSS 9.3) with Accompanying CVE-2026-19489 Memory Overflow (CVSS 8.8)](https://intel.threadlinqs.com/threat/TL-2026-2080) — CRITICAL · 2026-08-20

## Sources

Enriched from CVE.org, NVD, GitHub Security Advisories. Last verified by Threadlinqs on 2026-09-29. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [support.citrix.com](https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-19489
Full detection coverage and IOCs for threats exploiting CVE-2026-19489 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp