{"id":"CVE-2026-123306","kind":"vulnerability","aliases":["CVE-2026-123306"],"related":[],"title":"JetBrains IntelliJ IDEA: headless runs could add untrusted server certificates to trust store","description":"In JetBrains IntelliJ IDEA before 2026.3 improper checks allowed server certificates to be added to the trust store during headless runs","summary":"In JetBrains IntelliJ IDEA before 2026.3, improper checks let server certificates be added to the trust store during headless runs. An attacker positioned on the network path could get the IDE to trust a server it should reject.","severity":"high","cvss":7.4,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ci","intellij-idea","jetbrains","package"],"not_affected_if":["interactive-only-use","version-2026.3-or-later"],"how_to_check":"- Check the IntelliJ IDEA version in Help > About or the product info file; versions before `2026.3` are affected.\n- Note whether IDEA runs headless in CI or build jobs, since the flaw is limited to headless runs.","fix":"- JetBrains IntelliJ IDEA: `2026.3`","status":"open","published_at":"2026-11-06T11:17:09+00:00","first_seen_at":"2026-11-06T11:41:25+00:00","triaged_at":"2026-11-06T11:42:07+00:00","updated_at":"2026-11-06T11:42:07+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-06T11:42:07Z","model":"claude-haiku-5-5","output":{"fix":"- JetBrains IntelliJ IDEA: `2026.3`","reach":"network","title":"JetBrains IntelliJ IDEA: headless runs could add untrusted server certificates to trust store","impact":"medium","summary":"In JetBrains IntelliJ IDEA before 2026.3, improper checks let server certificates be added to the trust store during headless runs. An attacker positioned on the network path could get the IDE to trust a server it should reject.","audience":"developers","category":"package","nicknames":[],"who_cares":["intellij-idea","jetbrains","ci"],"confidence":0.6,"fix_status":"available","needs_auth":"unknown","worst_case":"Attacker-controlled certificate trusted, enabling man-in-the-middle on IDE connections","analyst_note":"Check the JetBrains advisory for exact headless conditions and which connections are affected; sources give only the one-line description.","how_to_check":"- Check the IntelliJ IDEA version in Help > About or the product info file; versions before `2026.3` are affected.\n- Note whether IDEA runs headless in CI or build jobs, since the flaw is limited to headless runs.","plain_action":"","needs_analyst":true,"not_affected_if":["interactive-only-use","version-2026.3-or-later"],"who_is_affected":"Teams running IntelliJ IDEA before 2026.3 in headless mode, such as CI or build jobs that use it for automated runs. Interactive desktop use of the IDE is described by the sources only as the headless case, so unknown beyond that.","user_interaction":"unknown","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000703,"input_tokens":4177,"output_tokens":571,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-123306':16A,19A '-2026':15A,18A '2026.3':31B,69C 'add':7A,38B,77C 'allow':72C 'attack':47B 'certif':10A,36B,74C 'check':33B,71C 'ci':20B 'could':6A,53B 'cve':14A,17A 'get':54B 'headless':4A,44B,83C 'ide':56B 'idea':3A,23B,29B,67C 'improp':32B,70C 'intellij':2A,22B,28B,66C 'intellij-idea':21B 'jetbrain':1A,24B,27B,65C 'let':34B 'network':51B 'packag':25B 'path':52B 'posit':48B 'reject':63B 'run':5A,45B,84C 'server':9A,35B,60B,73C 'store':13A,42B,81C 'trust':12A,41B,58B,80C 'untrust':8A","nicknames":[],"mitigations":[],"who_affected":"Teams running IntelliJ IDEA before 2026.3 in headless mode, such as CI or build jobs that use it for automated runs. Interactive desktop use of the IDE is described by the sources only as the headless case, so unknown beyond that.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ci","high","intellijidea","jetbrains","package"],"campaign_type":null,"search_a":"'-123306':16A,19A '-2026':15A,18A 'add':7A 'certif':10A 'could':6A 'cve':14A,17A 'headless':4A 'idea':3A 'intellij':2A 'jetbrain':1A 'run':5A 'server':9A 'store':13A 'trust':12A 'untrust':8A","search_b":"'2026.3':31B 'add':38B 'attack':47B 'certif':36B 'check':33B 'ci':20B 'could':53B 'get':54B 'headless':44B 'ide':56B 'idea':23B,29B 'improp':32B 'intellij':22B,28B 'intellij-idea':21B 'jetbrain':24B,27B 'let':34B 'network':51B 'packag':25B 'path':52B 'posit':48B 'reject':63B 'run':45B 'server':35B,60B 'store':42B 'trust':41B,58B","search_c":"'2026.3':69C 'add':77C 'allow':72C 'certif':74C 'check':71C 'headless':83C 'idea':67C 'improp':70C 'intellij':66C 'jetbrain':65C 'run':84C 'server':73C 'store':81C 'trust':80C","first_public_at":"2026-11-06T11:17:09+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","cvss_by":"cve@jetbrains.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123306","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123306","severity":null,"published_at":"2026-11-06T11:17:09+00:00","modified_at":"2026-11-06T11:17:09+00:00","first_seen_at":"2026-11-06T11:41:25+00:00","fetched_at":"2026-11-06T11:41:25+00:00","note":null}],"documents":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}