Citrix · NetScaler ADC and NetScaler Gateway
CVE-2026-8452
Memory overflow vulnerability leading to unpredictable or erroneous behavior and Denial of Service
What it is
Memory overflow vulnerability NetScaler ADC and NetScaler Gateway leading to unpredictable or erroneous behavior and Denial of Service if the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server
CISA: Citrix NetScaler ADC and NetScaler Gateway contain an improper restriction of operations within the bounds of a memory buffer vulnerability which could lead to 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: August 29, 2026
More exploited flaws from Citrix
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jan 17, 2024 | Code Injection | NetScaler ADC and NetScaler Gateway | Medium 5.5 | 3.2% |
| Jan 17, 2024 | Buffer Overflow | NetScaler ADC and NetScaler Gateway | High 8.2 | 58% |
| Oct 18, 2023 | Buffer Overflow | NetScaler ADC and NetScaler Gateway | Critical 9.4 | >99.9% |
| Jul 19, 2023 | Code Injection | NetScaler ADC and NetScaler Gateway | Critical 9.8 | 99.7% |
| Oct 4, 2026 | Improper Restriction of Operations within the Bounds of a Memory Buffer | NetScaler | High 8.7 | 11% |
| 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% |
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.