{"id":"CVE-2025-6543","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-6543","generatedAt":"2026-10-31T06:57:08.672Z","title":"Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability","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","published":"2025-06-25T13:15:27.000Z","lastModified":"2026-06-17T10:02:07.000Z","status":"Analyzed","sourceIdentifier":"secure@citrix.com","cvss":{"version":"4.0","score":9.2,"severity":"CRITICAL","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/M"},"cwe":["CWE-119"],"affected":["citrix/netscaler application delivery controller","citrix/netscaler gateway"],"epss":{"score":0.10433,"percentile":0.95731,"date":"2026-10-30","history":[]},"kev":{"listed":true,"dateAdded":"2025-06-30","dueDate":"2025-07-21","knownRansomwareCampaignUse":"Unknown","notes":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.\nhttps://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"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 21 July 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[],"references":[{"url":"https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788","tags":["Vendor Advisory"],"source":"secure@citrix.com"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-6543","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-6543","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}