{"cve":{"cve_id":"CVE-2026-88771","is_kev":true,"kev_date_added":"2026-09-27","kev_vendor_project":"Citrix","kev_product":"NetScaler","kev_vulnerability_name":"Citrix NetScaler Improper Input Validation Vulnerability","kev_short_description":"Citrix NetScaler ADC and NetScaler Gateway contain an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.","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":"2026-09-30","kev_known_ransomware":false,"kev_notes":"Running the provided IOCs in the NetScaler console may help identify indicators of exploitation. Customers must conduct forensic triage as directed by BOD 26‑04 and follow Citrix’s published guidance for mitigations. For more information, please see: https://community.citrix.com/techzone-blogs/110_security-updates/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve-2026-88771-through-cve-2026-88778 ; https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096 ; https://support.citrix.com/external/article/CTX694799/steps-to-take-if-netscaler-adc-is-suspec.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-2026-88772","kev_cwes":["CWE-119"],"epss_score":0.01083,"epss_percentile":0.64572,"epss_as_of":"2026-10-15","description":"Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.\n\nThis issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23 leading to an unauthenticated attacker to execute arbitrary commands.","published_at":"2026-09-27T16:02:07.001000Z","last_modified_at":"2026-09-29T04:18:01.603000Z","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":9.5,"cvss_v4_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","cvss_v4_severity":"CRITICAL","ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-20"],"nvd_references":["https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096"],"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":"2026-09-27T16:38:54.190028Z","updated_at":"2026-10-02T10:03:01.593453Z"},"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":"P","value_label":"Present"},{"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":"H","value_label":"High"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"H","value_label":"High"},{"metric":"SA","name":"Availability (Subsequent System)","value":"H","value_label":"High"}]},"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":"13.1.37.279","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-application-delivery-controller","product_name":"netscaler_application_delivery_controller","version_start":"13.1","version_start_inclusive":true,"version_end":"13.1-64.23","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":"13.1.37.279","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-gateway","product_name":"NetScaler Gateway","version_start":"13.1","version_start_inclusive":true,"version_end":"13.1-64.23","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*"},{"vendor_slug":"citrix-netscaler","vendor_name":"Citrix NetScaler","product_slug":"adc","product_name":"ADC","version_start":"0","version_start_inclusive":true,"version_end":"14.1-73.37","version_end_inclusive":false,"cpe23_uri":"cve5:citrix-netscaler:adc:0:14.1-73.37"},{"vendor_slug":"citrix-netscaler","vendor_name":"Citrix NetScaler","product_slug":"adc","product_name":"ADC","version_start":"0","version_start_inclusive":true,"version_end":"13.1-64.23","version_end_inclusive":false,"cpe23_uri":"cve5:citrix-netscaler:adc:0:13.1-64.23"},{"vendor_slug":"citrix-netscaler","vendor_name":"Citrix NetScaler","product_slug":"adc","product_name":"ADC","version_start":"0","version_start_inclusive":true,"version_end":"14.1-73.37 FIPS","version_end_inclusive":false,"cpe23_uri":"cve5:citrix-netscaler:adc:0:14.1-73.37 FIPS"},{"vendor_slug":"citrix-netscaler","vendor_name":"Citrix NetScaler","product_slug":"adc","product_name":"ADC","version_start":"0","version_start_inclusive":true,"version_end":"13.1.37.279 FIPS and NDcPP","version_end_inclusive":false,"cpe23_uri":"cve5:citrix-netscaler:adc:0:13.1.37.279 FIPS and NDcPP"},{"vendor_slug":"citrix-netscaler","vendor_name":"Citrix NetScaler","product_slug":"gateway","product_name":"Gateway","version_start":"0","version_start_inclusive":true,"version_end":"13.1-64.23","version_end_inclusive":false,"cpe23_uri":"cve5:citrix-netscaler:gateway:0:13.1-64.23"},{"vendor_slug":"citrix-netscaler","vendor_name":"Citrix NetScaler","product_slug":"gateway","product_name":"Gateway","version_start":"0","version_start_inclusive":true,"version_end":"14.1-73.37","version_end_inclusive":false,"cpe23_uri":"cve5:citrix-netscaler:gateway:0:14.1-73.37"}],"exploit_refs":[],"news":[{"id":2176,"source":"The Hacker News","url":"https://thehackernews.com/2026/09/cisa-says-attackers-are-exploiting-two.html","title":"CISA Says Attackers Are Exploiting Two Critical Citrix NetScaler Flaws Globally","summary":"The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Sunday added two critical Citrix NetScaler ADC and Gateway flaws to its Known Exploited Vulnerabilities (KEV) catalog, following reports of active exploitation.\n\nThe vulnerabilities are listed below -\n\n\n  CVE-2026-88771 (CVSS score: 9.5) - An improper input validation vulnerability that could allow an unauthenticated attacker to","thumbnail_url":"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjG1pBfETB-EOlAvKfZwROp5B3Nr3d00xBbxRPhsq5hDBvK8QTVYmc2r8tR8RNz7omvXWoufetWbVk1S-tZ74b-z0nxsHS_Zz7XnN4Vs7VGvDtlnOhsfG0ecx-LX_kuRwBLJwkIMN-26auGXjzdcAS2Yz8sdQ2U_kDtKpQOnOYD18r6WEu1twQ79p_ZJGhD/s1600/ct.jpg","author":"info@thehackernews.com (The Hacker News)","published_at":"2026-09-28T07:21:49Z","fetched_at":"2026-09-28T10:51:55.275452Z","trending_score":0.00006721702231483202,"cve_ids":["CVE-2026-88771"]}],"references":[{"url":"https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096","source_type":"MISC","tags":[]}],"timeline":[{"type":"cisa_reported","at":"2026-09-27T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"published","at":"2026-09-27T16:02:07.001000Z","label":"CVE published","source":null},{"type":"first_article","at":"2026-09-28T07:21:49Z","label":"First news coverage","source":"The Hacker News"},{"type":"cvss_changed","at":"2026-10-02T10:03:01.593453Z","label":"CVSS score revised","source":"nvd"},{"type":"cvss_changed","at":"2026-10-02T10:03:01.593453Z","label":"CVSS score revised","source":"nvd"},{"type":"cvss_changed","at":"2026-10-02T10:03:01.593453Z","label":"CVSS score revised","source":"nvd"}]}