CVE-2025-6543
KEVCitrix NetScaler ADC and Gateway Buffer Overflow Vulnerability
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.
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 4.0 vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/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:XPublishedJun 25, 2025
Last modifiedJun 17, 2026
Added to KEVJun 30, 2025
Remediation dueJul 21, 2025
References
- support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788Vendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-6543US Government Resource
0 recent articles mention this CVE
77
Risk assessment · High
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 462 days
- CVSS
- 9.2 CRITICAL
- EPSS (30-day exploit probability)
- 10.4% · top 4% of all CVEs
- Weakness
- CWE-119
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
Recommended actions
- 1.Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.