CVE DATABASE / CVE-2025-6543
CVE-2025-6543
Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability
Confirmed exploited in the wild. Added 2025-06-30.
Federal remediation due 2025-07-21.
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.
Summary
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
CVSS 3.1 breakdown
| Base score | 9.8 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity | HIGH |
| Availability | HIGH |
Weakness type (CWE)
Affected products
Use our free CVE Lookup tool for the latest NVD record, or browse the full CISA KEV catalog.
References
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-6543
Data: NIST NVD + CISA KEV. NVD last modified 2025-10-24. Always verify against the vendor advisory before acting.