Citrix · NetScaler ADC and Gateway
CVE-2025-5777
NetScaler ADC and NetScaler Gateway - Insufficient input validation leading to memory overread
What it is
Insufficient input validation leading to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server
CISA: Citrix NetScaler ADC and Gateway contain an out-of-bounds read vulnerability due to insufficient input validation. This vulnerability can lead to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Deadline for US federal agencies: July 11, 2025
More exploited flaws from Citrix
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jun 30, 2025 | Buffer Overflow | NetScaler ADC and Gateway | Critical 9.2 | 10% |
| 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% |
| Aug 26, 2026 | Improper Restriction of Operations within the Bounds of a Memory Buffer | NetScaler ADC and NetScaler Gateway | High 8.8 | 1.0% |
| Mar 30, 2026 | Out-of-Bounds Read | NetScaler | Critical 9.3 | 91% |
| Aug 26, 2025 | Memory Overflow | NetScaler | Critical 9.2 | 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.