{"cve":{"cve_id":"CVE-2023-4966","is_kev":true,"kev_date_added":"2023-10-18","kev_vendor_project":"Citrix","kev_product":"NetScaler ADC and NetScaler Gateway","kev_vulnerability_name":"Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability","kev_short_description":"Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for sensitive information disclosure when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.","kev_required_action":"Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.","kev_due_date":"2023-11-08","kev_known_ransomware":true,"kev_notes":"https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/, https://support.citrix.com/article/CTX579459/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20234966-and-cve20234967 ;  https://nvd.nist.gov/vuln/detail/CVE-2023-4966","kev_cwes":["CWE-119"],"epss_score":0.99999,"epss_percentile":0.99993,"epss_as_of":"2026-06-23","description":"Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA  virtual server.","published_at":"2023-10-10T13:12:17.644000Z","last_modified_at":null,"cvss_v3_score":9.4,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L","cvss_v3_severity":"CRITICAL","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"active","ssvc_automatable":true,"ssvc_technical_impact":"total","cwes":["CWE-119"],"nvd_references":["https://support.citrix.com/article/CTX579459","http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html"],"vuln_status":null,"trending_score":0.6099982000109744,"is_trending":true,"has_trended":true,"trended_number_one":false,"trending_peak_score":0.6099982000109744,"trending_peak_rank":24,"started_trending_at":"2026-06-29T02:30:27.366045Z","trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:31.350578Z","updated_at":"2026-06-29T02:30:27.550645Z"},"effective_severity":"CRITICAL","badges":["kev","ransomware","poc","trending","epss"],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"L","value_label":"Low"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-adc","product_name":"NetScaler ADC","version_start":"14.1","version_start_inclusive":true,"version_end":"8.50","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-adc:14.1:8.50"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-adc","product_name":"NetScaler ADC","version_start":"13.1","version_start_inclusive":true,"version_end":"49.15","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-adc:13.1:49.15"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-adc","product_name":"NetScaler ADC","version_start":"13.0","version_start_inclusive":true,"version_end":"92.19","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-adc:13.0:92.19"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-adc","product_name":"NetScaler ADC","version_start":"13.1-FIPS","version_start_inclusive":true,"version_end":"37.164","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-adc:13.1-FIPS:37.164"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-adc","product_name":"NetScaler ADC","version_start":"12.1-FIPS","version_start_inclusive":true,"version_end":"55.300","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-adc:12.1-FIPS:55.300"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-adc","product_name":"NetScaler ADC","version_start":"12.1-NDcPP","version_start_inclusive":true,"version_end":"55.300","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-adc:12.1-NDcPP:55.300"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-gateway","product_name":"NetScaler Gateway","version_start":"14.1","version_start_inclusive":true,"version_end":"8.50","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-gateway:14.1:8.50"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-gateway","product_name":"NetScaler Gateway","version_start":"13.1","version_start_inclusive":true,"version_end":"49.15","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-gateway:13.1:49.15"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-gateway","product_name":"NetScaler Gateway","version_start":"13.0","version_start_inclusive":true,"version_end":"92.19","version_end_inclusive":false,"cpe23_uri":"cve5:citrix:netscaler-gateway:13.0:92.19"}],"exploit_refs":[{"source":"nuclei","kind":"nuclei","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-4966.yaml","title":"Citrix Bleed - Leaking Session Tokens","author":"DhiyaneshDK","disclosed_at":null}],"news":[],"references":[{"url":"https://support.citrix.com/article/CTX579459","source_type":"MISC","tags":[]},{"url":"http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html","source_type":"EXPLOIT","tags":["exploit"]}],"timeline":[{"type":"published","at":"2023-10-10T13:12:17.644000Z","label":"CVE published","source":null},{"type":"cisa_reported","at":"2023-10-18T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"poc_available","at":"2026-06-24T00:29:48.638073Z","label":"Public PoC available","source":"nuclei"},{"type":"cvss_changed","at":"2026-06-28T17:30:54.274701Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:30:54.274701Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:30:54.274701Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"ssvc_changed","at":"2026-06-29T01:41:37.767234Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:41:37.767234Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:41:37.767234Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"started_trending","at":"2026-06-29T02:30:27.366045Z","label":"Started trending","source":null}]}