June 30, 2025 · Applied Cybernetics Group
CVE-2025-6543 — Citrix NetScaler ADC and Gateway
Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability
- Added to KEV
2025-06-30- Federal due date
2025-07-21- Vendor
- Citrix
- Product
- NetScaler ADC and Gateway
- EPSS
- 95.0th percentile (score 0.098, as of
2026-07-13) - NVD CVSS v3.1
- 9.8 (CRITICAL)
- Ransomware use
- Unknown
- ATT&CK
- T1059 , T1203 , T1498 · signal rollup
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2025-6543
CISA short description
Citrix NetScaler ADC and Gateway contain a buffer overflow vulnerability leading to unintended control flow and Denial of Service. NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
NVD description
Memory overflow vulnerability leading to unintended control flow and Denial of Service in NetScaler ADC and NetScaler Gateway when configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server