{"cve":{"cve_id":"CVE-2026-19490","is_kev":true,"kev_date_added":"2026-09-09","kev_vendor_project":"Citrix","kev_product":"NetScaler","kev_vulnerability_name":"Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability","kev_short_description":"Citrix NetScaler ADC and NetScaler Gateway contain an authentication-bypass vulnerability involving an alternate path or channel. When the NetScaler appliance is configured as an AAA virtual server or as a Gateway (SSL VPN, ICA Proxy, CVPN, or RDP Proxy), an unauthenticated remote threat actor may be able to bypass authentication.","kev_required_action":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","kev_due_date":"2026-09-12","kev_known_ransomware":false,"kev_notes":"https://support.citrix.com/external/article/CTX696939/netscaler-adc-and-netscaler-gateway-secu.html ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-19490","kev_cwes":["CWE-288"],"epss_score":0.23158,"epss_percentile":0.97744,"epss_as_of":"2026-10-15","description":"Vulnerability in NetScaler ADC and NetScaler Gateway.\n\nThis issue affects ADC: from 14.1 through 73.32 and from 13.1 through 63.21; Gateway: from 14.1 through 73.32 and from 13.1 through 63.21.","published_at":"2026-08-19T12:54:39.730000Z","last_modified_at":"2026-10-07T19:17:36.500000Z","cvss_v3_score":9.8,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_v3_severity":"CRITICAL","cvss_v4_score":9.3,"cvss_v4_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L","cvss_v4_severity":"CRITICAL","ssvc_decision":null,"ssvc_exploitation":"none","ssvc_automatable":true,"ssvc_technical_impact":"total","cwes":["CWE-288"],"nvd_references":["https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939"],"vuln_status":"Analyzed","trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-08-19T14:42:27.513060Z","updated_at":"2026-10-08T21:36:59.234326Z"},"effective_severity":"CRITICAL","badges":["kev","news"],"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":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":"4.0","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"AT","name":"Attack Requirements","value":"N","value_label":"None"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"VC","name":"Confidentiality (Vulnerable System)","value":"H","value_label":"High"},{"metric":"VI","name":"Integrity (Vulnerable System)","value":"H","value_label":"High"},{"metric":"VA","name":"Availability (Vulnerable System)","value":"H","value_label":"High"},{"metric":"SC","name":"Confidentiality (Subsequent System)","value":"L","value_label":"Low"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"L","value_label":"Low"},{"metric":"SA","name":"Availability (Subsequent System)","value":"L","value_label":"Low"}]},"affected":[{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-application-delivery-controller","product_name":"netscaler_application_delivery_controller","version_start":"13.1","version_start_inclusive":true,"version_end":"13.1-37.277","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-application-delivery-controller","product_name":"netscaler_application_delivery_controller","version_start":"13.1","version_start_inclusive":true,"version_end":"13.1-63.21","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-application-delivery-controller","product_name":"netscaler_application_delivery_controller","version_start":"13.1","version_start_inclusive":true,"version_end":"13.1-37.277","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:*"},{"vendor_slug":"citrix","vendor_name":"Citrix","product_slug":"netscaler-gateway","product_name":"NetScaler Gateway","version_start":"13.1","version_start_inclusive":true,"version_end":"13.1-63.21","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*"},{"vendor_slug":"netscaler","vendor_name":"NetScaler","product_slug":"adc","product_name":"ADC","version_start":"13.1","version_start_inclusive":true,"version_end":"63.21","version_end_inclusive":true,"cpe23_uri":"cve5:netscaler:adc:13.1:63.21"},{"vendor_slug":"netscaler","vendor_name":"NetScaler","product_slug":"adc","product_name":"ADC","version_start":"14.1","version_start_inclusive":true,"version_end":"73.32","version_end_inclusive":true,"cpe23_uri":"cve5:netscaler:adc:14.1:73.32"},{"vendor_slug":"netscaler","vendor_name":"NetScaler","product_slug":"gateway","product_name":"Gateway","version_start":"13.1","version_start_inclusive":true,"version_end":"63.21","version_end_inclusive":true,"cpe23_uri":"cve5:netscaler:gateway:13.1:63.21"},{"vendor_slug":"netscaler","vendor_name":"NetScaler","product_slug":"gateway","product_name":"Gateway","version_start":"14.1","version_start_inclusive":true,"version_end":"73.32","version_end_inclusive":true,"cpe23_uri":"cve5:netscaler:gateway:14.1:73.32"}],"exploit_refs":[],"news":[{"id":1695,"source":"BleepingComputer","url":"https://www.bleepingcomputer.com/news/security/hackers-target-critical-citrix-netscaler-auth-bypass-in-attacks/","title":"Critical Citrix NetScaler auth bypass now leveraged in attacks","summary":"Attackers have begun targeting a critical-severity Citrix NetScaler auth bypass flaw (CVE-2026-19490) in the wild, according to vulnerability intelligence company Previdian. [...]","thumbnail_url":null,"author":"Sergiu Gatlan","published_at":"2026-09-04T15:25:59Z","fetched_at":"2026-09-04T15:32:30.426596Z","trending_score":1.954704863776318e-8,"cve_ids":["CVE-2026-19490"]}],"references":[{"url":"https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2026-08-19T12:54:39.730000Z","label":"CVE published","source":null},{"type":"ssvc_changed","at":"2026-08-20T14:43:27.513747Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-08-20T14:43:27.513747Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-08-20T14:43:27.513747Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"first_article","at":"2026-09-04T15:25:59Z","label":"First news coverage","source":"BleepingComputer"},{"type":"cisa_reported","at":"2026-09-09T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"cvss_changed","at":"2026-09-10T23:39:39.813751Z","label":"CVSS score revised","source":"nvd"},{"type":"cvss_changed","at":"2026-09-10T23:39:39.813751Z","label":"CVSS score revised","source":"nvd"},{"type":"cvss_changed","at":"2026-09-10T23:39:39.813751Z","label":"CVSS score revised","source":"nvd"}]}