Citrix patches 28 NetScaler flaws, one critical on default installs
CVE-2026-120868, a CVSS 9.3 memory overflow, needs no login or special feature and can crash any unpatched appliance.
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CVE-2026-120865
HTTP/3 memory overflow DoS in Citrix NetScaler ADC and Gateway
- CVSS 4.0
- 8.7 high
- EPSS
- —
- Published
- ·
- Modified
AI analysisSummaries by Vani AI
A memory overflow in HTTP/3 (QUIC) on Citrix NetScaler ADC and Citrix NetScaler Gateway can cause unpredictable or erroneous behavior or a denial of service. A remote attacker can trigger it over the network with no authentication and no user interaction. The primary impact is availability loss on those appliances; confidentiality and integrity of the vulnerable system are not affected.
What to do: Apply Citrix's update for CVE-2026-120865. Citrix has not listed affected or fixed builds.
| Product | Affected |
|---|---|
| Citrix NetScaler ADC | — |
| Citrix NetScaler Gateway | — |
Estimated exposure
No basis for an estimate.
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description · NVD
Memory overflow in HTTP/3 (QUIC) can lead to unpredictable or erroneous behavior or Denial of Service in Citrix NetScaler ADC and Citrix NetScaler Gateway.
- Vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X