Multiple Critical Vulnerabilities Found in Citrix NetScaler ADC and Gateway, Two Actively Exploited

Cloud Software Group disclosed eight vulnerabilities affecting NetScaler ADC and NetScaler Gateway products on September 27, 2026. Two of the issues, CVE-2026-88771 and CVE-2026-88772, have already been confirmed as exploited in the wild, prompting urgent remediation advice. CVE-2026-88771 stems from insufficient input validation and allows unauthenticated remote code execution across all default configurations. CVE-2026-88772 involves a memory overflow that can lead to code execution or denial of service when DTLS is enabled, which occurs by default on VPN vServers. The remaining six vulnerabilities cover code execution, denial of service, and HTTP request smuggling risks, with the advisory rated Critical overall. Organizations are urged to apply patches immediately and investigate potential breaches.

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Cloud Software Group has disclosed multiple vulnerabilities in its NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway) products. The security advisory published on September 27, 2026, details eight CVEs that include risks of remote code execution, denial of service, and HTTP request smuggling.

The company rated the overall advisory as Critical. Two vulnerabilities stand out because active exploitation has already been confirmed: CVE-2026-88771 and CVE-2026-88772.

CVE-2026-88771 is caused by improper input validation. It permits unauthenticated attackers to execute arbitrary commands. Every affected environment, including default configurations, is impacted.

CVE-2026-88772 results from a memory overflow condition. Successful exploitation can lead to arbitrary code execution or a denial-of-service condition. The flaw affects systems where Datagram Transport Layer Security (DTLS) is enabled. Because DTLS is enabled by default on VPN vServer instances, a wide range of deployments require immediate attention.

Security teams should review the official bulletins CTX697096 and the NetScaler Security Bulletin for CVE-2026-88771 through CVE-2026-88778, apply available patches without delay, and conduct forensic investigations for signs of prior compromise.

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