CVE-2025-6543
CRITICAL CISA KEVCVSS v3
9.8
CRITICAL
EPSS Score
0.9%
exploit probability
CISA KEV
Yes
known exploited
Exploitation
—
SSVC status
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
CISA Known Exploited Vulnerability
- Date Added
- 6/30/2025
- Patch Due Date
- 7/21/2025
- 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.
Technical Details
- CVSS v3 Vector
- 3.1
- Published
- 6/25/2025
- Last Modified
- 6/17/2026
Frequently Asked Questions
What is CVE-2025-6543?
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
Is CVE-2025-6543 actively exploited?
Yes. CVE-2025-6543 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 7/21/2025.
What is the CVSS score for CVE-2025-6543?
CVE-2025-6543 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string 3.1.
Is CVE-2025-6543 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.