CVE-2025-6543: Memory overflow vulnerability leading to unintended control flow and Denial of Service
Critical · CVSS 9.8 (CVSS 3.1)KEV known exploitedEPSS 10.4%, 96th percentilePublished Updated Assigner: Citrix
In CISA’s Known Exploited Vulnerabilities catalog: Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability.
Added , federal remediation due . Known ransomware use: Unknown.
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.
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
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H · CWE-119
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
NetScaler: ADCNetScaler: Gateway
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- support.citrix.com/support-home/kbsearch/article (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)