{"id":"CVE-2026-12254","kind":"vulnerability","aliases":["CVE-2026-12254"],"related":[],"title":"Netskope client: captive portal stays open, enabling rogue access point abuse","description":"Netskope is notified about a potential gap in its agent (NSClient) where a system with Netskope Client while connecting to an access point with Captive Portal switches to a Network which already has internet connectivity, the Captive Portal does not close. This allows the possibility of abuse via the Captive Portal using a rogue access point to either access malicious sites or exfiltrate data.The issue impacts all versions prior to R142","summary":"The Netskope Client agent (NSClient) can leave a captive portal open when a device switches to a network that already has internet access. An attacker running a rogue access point can use that gap to direct traffic to malicious sites or exfiltrate data.","severity":"medium","cvss":6.4,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["captive-portal","endpoint","laptops","netskope","other","wifi"],"not_affected_if":["not-netskope-client","r142-or-later"],"how_to_check":"- Check the installed Netskope Client version against the fixed release R142 or later\n- unknown","fix":"- Upgrade the Netskope Client to `R142` or later\n- unknown","status":"open","published_at":"2026-10-19T16:17:07+00:00","first_seen_at":"2026-10-23T21:57:18+00:00","triaged_at":"2026-10-25T03:59:33+00:00","updated_at":"2026-10-25T03:59:33+00:00","category":"other","confidence":0.6,"triage":{"at":"2026-10-25T03:59:33Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade the Netskope Client to `R142` or later\n- unknown","reach":"local","title":"Netskope client: captive portal stays open, enabling rogue access point abuse","impact":"medium","summary":"The Netskope Client agent (NSClient) can leave a captive portal open when a device switches to a network that already has internet access. An attacker running a rogue access point can use that gap to direct traffic to malicious sites or exfiltrate data.","category":"other","nicknames":[],"who_cares":["netskope","endpoint","laptops","captive-portal","wifi"],"confidence":0.6,"needs_auth":"no","worst_case":"Traffic redirected to malicious sites or sensitive data exfiltrated","analyst_note":"Check the Netskope advisory for the exact affected version range, whether any user action is required, and the exposure to the rogue AP attack path; the sources here only give the NVD description.","how_to_check":"- Check the installed Netskope Client version against the fixed release R142 or later\n- unknown","needs_analyst":true,"not_affected_if":["not-netskope-client","r142-or-later"],"who_is_affected":"Endpoints running the Netskope Client (NSClient) before R142 that connect to Wi-Fi networks with captive portals, particularly in environments where users roam between networks. Systems not running the Netskope Client are not described as affected by this issue.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000591,"input_tokens":3347,"output_tokens":512,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-12254':14A,17A '-2026':13A,16A 'abus':11A,115C 'access':9A,48B,54B,90C,123C,127C 'agent':29B,78C 'allow':111C 'alreadi':45B,100C 'attack':50B 'captiv':3A,19B,34B,93C,105C,118C 'captive-port':18B 'client':2A,28B,85C 'close':109C 'connect':87C,103C 'cve':12A,15A 'data':68B 'data.the':132C 'devic':39B 'direct':61B 'either':126C 'enabl':7A 'endpoint':21B 'exfiltr':67B,131C 'gap':59B,75C 'impact':134C 'internet':47B,102C 'issu':133C 'laptop':22B 'leav':32B 'malici':64B,128C 'netskop':1A,23B,27B,69C,84C 'network':43B,98C 'notifi':71C 'nsclient':30B,79C 'open':6A,36B 'point':10A,55B,91C,124C 'portal':4A,20B,35B,94C,106C,119C 'possibl':113C 'potenti':74C 'prior':137C 'r142':139C 'rogu':8A,53B,122C 'run':51B 'site':65B,129C 'stay':5A 'switch':40B,95C 'system':82C 'traffic':62B 'use':57B,120C 'version':136C 'via':116C 'wifi':25B","nicknames":[],"mitigations":[],"who_affected":"Endpoints running the Netskope Client (NSClient) before R142 that connect to Wi-Fi networks with captive portals, particularly in environments where users roam between networks. Systems not running the Netskope Client are not described as affected by this issue.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-19T16:17:07+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/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":"psirt@netskope.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-12254","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12254","severity":null,"published_at":"2026-10-19T16:17:07+00:00","modified_at":"2026-10-20T20:17:20+00:00","first_seen_at":"2026-10-23T21:57:18+00:00","fetched_at":"2026-10-23T22:28:57+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}