CVE-2026-88778

TCP Initial Sequence Number (ISN) prediction

CVSS 8.8 high · Citrix NetScaler ADC · published 2026-09-27

Predictable exact value from previous values 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.

NVD · CVE.org

Coverage 1 source

1. 2026-09-27 CISA Cybersecurity Advisories critical Critical Zero-Day Vulnerabilities Exploited in Citrix NetScaler ADC, Gateway

   Citrix NetScaler ADC and Gateway have eight new vulnerabilities, including two critical zero-days exploited in the wild.

Mentioned with

CVE-2026-88771 CVE-2026-88772 CVE-2026-88773 CVE-2026-88774 CVE-2026-88775 CVE-2026-88776 CVE-2026-88777

Also covered

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• CVE-2026-88772 Memory overflow vulnerability leading to Remote Code Execution or Denial of Service CVSS 9.5 · 3 articles · 2026-09-28
• CVE-2026-88771 A remote code execution vulnerability exists due to improper input validation, which can allow an unauthenticated attacker to execute arbitrary commands CVSS 9.5 · 3 articles · 2026-09-28