{"id":"CVE-2026-111341","kind":"vulnerability","aliases":["CVE-2026-111341"],"related":[],"title":"Citrix NetScaler: memory overflow in client-certificate login causes crashes","description":"Memory overflow in client-certificate authentication can lead to unpredictable or erroneous behavior or Denial of Service in Citrix NetScaler ADC and Citrix NetScaler Gateway.","summary":"A memory overflow in the client-certificate authentication path of Citrix NetScaler ADC and NetScaler Gateway can cause unpredictable or erroneous behavior. The sources say it can also lead to a denial of service.","severity":"high","cvss":8.7,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Citrix NetScaler ADC","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"NetScaler ADC","fixed":["14.1-73.57","13.1-64.39","14.1-73.58 FIPS","13.1-37.293"],"affected":"14.1 < 14.1-73.57; 13.1 < 13.1-64.39; 14.1-FIPS < 14.1-73.58; 13.1-FIPS/NDcPP < 13.1-37.293","ecosystem":"vendor"},{"name":"NetScaler Gateway","fixed":["14.1-73.57","13.1-64.39"],"affected":"14.1 < 14.1-73.57; 13.1 < 13.1-64.39","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["citrix","client-certificate","infrastructure","netscaler","netscaler-gateway","self-hosted"],"not_affected_if":["managed-hosting","no-certaction"],"how_to_check":"Exposed only if the appliance is configured with a certificate authentication action (CertAction) on NetScaler ADC or Gateway. Inspect the running configuration for a certificate auth action and check the build with 'show version'; builds older than the fixed ones above are affected. Citrix's bulletin points to inspecting the NetScaler configuration for this precondition.","fix":"Upgrade to NetScaler ADC/Gateway 14.1-73.57 or later, 13.1-64.39 or later (13.1), 14.1-FIPS 14.1-73.58 FIPS or later, or 13.1-FIPS/13.1-NDcPP 13.1-37.293 or later. Customer-managed only; Citrix-managed cloud services are upgraded by Cloud Software Group.","status":"open","published_at":"2026-11-13T04:17:36+00:00","first_seen_at":"2026-11-13T04:42:39+00:00","triaged_at":"2026-11-13T04:43:50+00:00","updated_at":"2026-11-13T04:44:55+00:00","category":"infrastructure","confidence":0.85,"triage":{"at":"2026-11-13T04:43:50Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"unknown","title":"Citrix NetScaler: memory overflow in client-certificate login causes crashes","impact":"medium","summary":"A memory overflow in the client-certificate authentication path of Citrix NetScaler ADC and NetScaler Gateway can cause unpredictable or erroneous behavior. The sources say it can also lead to a denial of service.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["citrix","netscaler","netscaler-gateway"],"confidence":0.5,"fix_status":"unknown","needs_auth":"unknown","worst_case":"Appliance crashes or behaves erratically, causing denial of service","analyst_note":"Find the affected and fixed versions and the exact client-certificate configuration from Citrix's advisory or the NVD entry.","how_to_check":"unknown","plain_action":"","product_name":"Citrix NetScaler ADC","needs_analyst":true,"not_affected_if":[],"who_is_affected":"The sources say the flaw affects Citrix NetScaler ADC and NetScaler Gateway when client-certificate authentication is used. They do not state the affected versions or the exact configuration required. unknown","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000688,"input_tokens":4520,"output_tokens":472,"severity_before":"high"},"analyst_status":"done","analyst_note":"Find the affected and fixed versions and the exact client-certificate configuration from Citrix's advisory or the NVD entry.","search":"'-111341':14A,17A '-2026':13A,16A 'adc':20A,22A,50B,93C 'also':65B 'authent':45B,78C 'behavior':59B,85C 'caus':10A,55B 'certif':8A,28B,44B,77C 'citrix':1A,18A,25B,48B,91C,95C 'client':7A,27B,43B,76C 'client-certif':6A,26B,42B,75C 'crash':11A 'cve':12A,15A 'denial':69B,87C 'erron':58B,84C 'gateway':24A,33B,53B,97C 'host':36B 'infrastructur':29B 'lead':66B,80C 'login':9A 'memori':3A,38B,72C 'netscal':2A,30B,32B,49B,52B,92C,96C 'netscaler':19A,21A,23A 'netscaler-gateway':31B 'overflow':4A,39B,73C 'path':46B 'say':62B 'self':35B 'self-host':34B 'servic':71B,89C 'sourc':61B 'unpredict':56B,82C","nicknames":[],"mitigations":[],"who_affected":"Customer-managed Citrix NetScaler ADC and Gateway appliances that have a certificate authentication action (CertAction) configured. Appliances without one, and Citrix-managed cloud services, can skip it. Impact per Citrix is erratic behavior or denial of service.","tier":"B","verified":{"fix":{"at":"2026-11-13T04:44:55Z","by":"analyst","doc":"https://support.citrix.com/external/article/CTX697305","run_id":3819}},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":["adc","citrixnetscaleradc","gateway","netscaleradc","netscalergateway"],"ptokens":["adc","citrix","gateway","netscaler"],"labels":["citrix","clientcertificate","high","infrastructure","netscaler","netscalergateway","selfhosted","vendor"],"campaign_type":null,"search_a":"'-111341':14A,17A '-2026':13A,16A 'adc':20A,22A 'caus':10A 'certif':8A 'citrix':1A,18A 'client':7A 'client-certif':6A 'crash':11A 'cve':12A,15A 'gateway':24A 'login':9A 'memori':3A 'netscal':2A 'netscaler':19A,21A,23A 'overflow':4A","search_b":"'adc':50B 'also':65B 'authent':45B 'behavior':59B 'caus':55B 'certif':28B,44B 'citrix':25B,48B 'client':27B,43B 'client-certif':26B,42B 'denial':69B 'erron':58B 'gateway':33B,53B 'host':36B 'infrastructur':29B 'lead':66B 'memori':38B 'netscal':30B,32B,49B,52B 'netscaler-gateway':31B 'overflow':39B 'path':46B 'say':62B 'self':35B 'self-host':34B 'servic':71B 'sourc':61B 'unpredict':56B","search_c":"'adc':93C 'authent':78C 'behavior':85C 'certif':77C 'citrix':91C,95C 'client':76C 'client-certif':75C 'denial':87C 'erron':84C 'gateway':97C 'lead':80C 'memori':72C 'netscal':92C,96C 'overflow':73C 'servic':89C 'unpredict':82C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-13T04:17:36+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"50a63c94-1ea7-4568-8c11-eb79e7c5a2b5","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-111341","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-111341","severity":null,"published_at":"2026-11-13T04:17:36+00:00","modified_at":"2026-11-13T04:17:36+00:00","first_seen_at":"2026-11-13T04:42:39+00:00","fetched_at":"2026-11-13T04:42:39+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-111341:3819","url":"https://support.citrix.com/external/article/CTX697305","severity":null,"published_at":"2026-11-13T04:44:55+00:00","modified_at":"2026-11-13T04:44:55+00:00","first_seen_at":"2026-11-13T04:44:55+00:00","fetched_at":"2026-11-13T04:44:55+00:00","note":"Read Citrix CTX697305: precondition is a certificate authentication action (CertAction); fixed builds listed. Affected = anything before fixed builds (stated in bulletin as upgrade targets; 'before' ranges seen only in Kraft Kennedy rewrite). No exploitation or PoC mentioned in bulletin. Bulletin text was truncated before the vendor's check instructions.","cites":["https://support.citrix.com/external/article/CTX697305"]}],"documents":[{"id":142058,"url":"https://support.citrix.com/external/article/CTX697305","title":"Citrix NetScaler ADC and Gateway Security Bulletin CTX697305","kind":"advisory","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"advisory","confidence":null,"note":null}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}