Critical Zero-Day Vulnerabilities Disclosed in Citrix NetScaler Products

• •Two critical zero-day vulnerabilities in Citrix NetScaler products have been disclosed.
• •CVE-2026-88771 and CVE-2026-88772 allow remote code execution and have a CVSS score of 9.5.
• •Exploitation of these vulnerabilities has been confirmed in the wild, with attacks reported as early as September 24.

Citrix disclosed critical vulnerabilities affecting its NetScaler ADC and Gateway products, with CVE-2026-88771 and CVE-2026-88772 being particularly severe. Both vulnerabilities have a CVSS score of 9.5, allowing remote code execution and potential denial-of-service attacks. Reports of exploitation began circulating on September 25, prompting Citrix to release patches on September 27. Security experts noted that attacks had likely been occurring for at least a week prior to the disclosure. Users were advised to disable their NetScaler appliances until the vulnerabilities could be mitigated. The vulnerabilities affect default configurations, making many deployments susceptible to attacks. Citrix's advisory emphasized the urgency for customers to update their software immediately.