Defending Against Active Exploitation of Citrix NetScaler ADC and Gateway Appliances
Introduction In late September 2026, Mandiant Consulting and Google Threat Intelligence Group (GTIG) identified active, in-the-wild exploitation of a zero-day vulnerability (CVE-2026-88772) affecting Citrix NetScaler ADC and NetScaler Gateway appliances.
Summary from Google Threat Intelligence.
Explained
The technology and terms in this story. Learn more
- ConceptZero-dayA flaw attackers exploit before the vendor has a fix: defenders have had zero days to patch.
- TechnologyPHPA programming language that powers a large share of websites, including WordPress.
- ConceptExploitCode or a technique that turns a software flaw into something an attacker can actually use.
- ConceptCVE · Common Vulnerabilities and ExposuresThe public ID system for vulnerabilities, such as CVE-2026-12345, so everyone means the same bug.
Why it was possible
The weaknesses behind this story's CVEs, from each CVE Record.
Vulnerabilities in this story
Severity and exploitation facts from NVD, FIRST, and CISA.
Related coverage
Other sources covering the same vulnerabilities or event.