Citrix · NetScaler
CVE-2026-88779
Memory overflow vulnerability leading to Denial of Service
What it is
Vulnerability in NetScaler ADC and NetScaler Gateway.
This issue affects ADC: before 14.1-73.41, before 13.1-64.28, before 14.1-73.41 FIPS, and before 13.1-37.282; Gateway: before 14.1-73.41 and before 13.1-64.28.
CISA: Citrix NetScaler ADC (formerly Citrix ADC) and Citrix NetScaler Gateway (formerly Citrix Gateway) contain an improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for a denial of service.
What to do
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Deadline for US federal agencies: October 7, 2026
More exploited flaws from Citrix
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Sep 27, 2026 | Improper Input Validation | NetScaler | Critical 9.5 | 82% |
| Sep 27, 2026 | Improper Restriction of Operations within the Bounds of a Memory Buffer | NetScaler | Critical 9.5 | 78% |
| Sep 9, 2026 | Authentication Bypass Using an Alternate Path or Channel | NetScaler | Critical 9.3 | 33% |
| Mar 30, 2026 | Out-of-Bounds Read | NetScaler | Critical 9.3 | 91% |
| Aug 26, 2025 | Memory Overflow | NetScaler | Critical 9.2 | 21% |
| Aug 26, 2026 | Improper Restriction of Operations within the Bounds of a Memory Buffer | NetScaler ADC and NetScaler Gateway | High 8.8 | 1.0% |
| Aug 25, 2025 | Improper Privilege Management | Session Recording | Medium 5.1 | 3.5% |
| Aug 25, 2025 | Deserialization of Untrusted Data | Session Recording | Medium 5.1 | 21% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.