CVE-2025-6543 · netVigilance record NV25-0132
Citrix NetScaler ADC and Gateway Buffer Overflow
past due
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA deadline 2025-07-21 · passed 1 year 1 month ago · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
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.
Who is affected
Citrix NetScaler ADC and Gateway. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-119.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinepassed 1 year 1 month ago
Sources
- NVD entry for CVE-2025-6543 nvd.nist.gov/vuln/detail/CVE-2025-6543
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- support.citrix.com support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788
- netscaler.com www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2025-6543