CVE-2026-8452 Citrix NetScaler ADC and NetScaler Gateway Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
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.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 26 Aug 2026.
- Rated High severity (CVSS 8.8, scored by Vendor).
- This product type is often exposed to the internet, which is where attackers scan for it first.
- It has been in the catalogue for 72 days. Systems still unpatched now have almost certainly been scanned for it.
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
Affected Versions
| Product | Versions |
|---|---|
| NetScaler ADC | 14.1 to before 72.61 13.1 to before 63.18 14.1 FIPS to before 72.61 13.1 FIPS and NDcPP to before 37.272 |
| NetScaler Gateway | 14.1 to before 72.61 13.1 to before 63.18 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Citrix NetScaler ADC and NetScaler Gateway. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
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.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2026-8452 and every other exploited flaw on the list.