CVE-2025-6543
Memory overflow vulnerability leading to unintended control flow and Denial of Service
Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
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.
CISA notes
https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788 ; https://www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/ ; https://nvd.nist.gov/vuln/detail/CVE-2025-6543
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
Severity
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:LAffected Products
| Vendor | Product | Affected versions |
|---|---|---|
| NetScaler | ADC | 14.1 to <47.46 13.1 to <59.19 13.1 FIPS and NDcPP to <37.236 |
| NetScaler | Gateway | 14.1 to <47.46 13.1 to <59.19 13.1 FIPS and NDcPP to <37.236 |
References
1 LinksRecord Details
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Insufficient input validation leading to memory overread
Related Tool Categories
Tool categories that test for or protect against this vulnerability class.
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