{"id":"CVE-2026-123844","kind":"vulnerability","aliases":["CVE-2026-123844"],"related":[],"title":"JetBrains IntelliJ IDEA: custom plugin repositories allow server-side request forgery","description":"In JetBrains IntelliJ IDEA before 2026.3 sSRF was possible via custom plugin repositories","summary":"IntelliJ IDEA before 2026.3 could be made to send server-side requests to addresses an attacker chooses through custom plugin repository settings. An attacker could use the IDE to reach internal services the developer's machine can see.","severity":"medium","cvss":5.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ide","intellij-idea","java","jetbrains","package"],"not_affected_if":["default-plugin-repository-only","version-2026.3-or-later"],"how_to_check":"- Check the IntelliJ IDEA version under Help > About; versions before `2026.3` are affected.\n- Check whether custom plugin repositories are configured under Settings > Plugins > Manage Plugin Repositories.","fix":"- Move IntelliJ IDEA to `2026.3` or later.","status":"open","published_at":"2026-11-06T17:17:23+00:00","first_seen_at":"2026-11-06T17:43:13+00:00","triaged_at":"2026-11-06T17:45:32+00:00","updated_at":"2026-11-06T17:45:32+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-06T17:45:32Z","model":"claude-haiku-5-5","output":{"fix":"- Move IntelliJ IDEA to `2026.3` or later.","reach":"network","title":"JetBrains IntelliJ IDEA: custom plugin repositories allow server-side request forgery","impact":"low","summary":"IntelliJ IDEA before 2026.3 could be made to send server-side requests to addresses an attacker chooses through custom plugin repository settings. An attacker could use the IDE to reach internal services the developer's machine can see.","audience":"developers","category":"package","nicknames":[],"who_cares":["intellij-idea","jetbrains","java","ide"],"confidence":0.6,"fix_status":"available","needs_auth":"unknown","worst_case":"server-side requests reach internal hosts the developer's machine can access","analyst_note":"","how_to_check":"- Check the IntelliJ IDEA version under Help > About; versions before `2026.3` are affected.\n- Check whether custom plugin repositories are configured under Settings > Plugins > Manage Plugin Repositories.","plain_action":"","needs_analyst":false,"not_affected_if":["default-plugin-repository-only","version-2026.3-or-later"],"who_is_affected":"Developers who run IntelliJ IDEA older than 2026.3 and have custom plugin repositories configured are the ones exposed. Users who only use the default JetBrains plugin repository are less exposed. The sources do not say more about the exact conditions.","user_interaction":"unknown","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.00068,"input_tokens":4166,"output_tokens":526,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-123844':15A,18A '-2026':14A,17A '2026.3':29B,70C 'address':40B 'allow':7A 'attack':42B,50B 'choos':43B 'could':30B,51B 'custom':4A,45B,75C 'cve':13A,16A 'develop':60B 'forgeri':12A 'ide':19B,54B 'idea':3A,22B,27B,68C 'intellij':2A,21B,26B,67C 'intellij-idea':20B 'intern':57B 'java':23B 'jetbrain':1A,24B,66C 'machin':62B 'made':32B 'packag':25B 'plugin':5A,46B,76C 'possibl':73C 'reach':56B 'repositori':6A,47B,77C 'request':11A,38B 'see':64B 'send':34B 'server':9A,36B 'server-sid':8A,35B 'servic':58B 'set':48B 'side':10A,37B 'ssrf':71C 'use':52B 'via':74C","nicknames":[],"mitigations":[],"who_affected":"Developers who run IntelliJ IDEA older than 2026.3 and have custom plugin repositories configured are the ones exposed. Users who only use the default JetBrains plugin repository are less exposed. The sources do not say more about the exact conditions.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ide","intellijidea","java","jetbrains","medium","package"],"campaign_type":null,"search_a":"'-123844':15A,18A '-2026':14A,17A 'allow':7A 'custom':4A 'cve':13A,16A 'forgeri':12A 'idea':3A 'intellij':2A 'jetbrain':1A 'plugin':5A 'repositori':6A 'request':11A 'server':9A 'server-sid':8A 'side':10A","search_b":"'2026.3':29B 'address':40B 'attack':42B,50B 'choos':43B 'could':30B,51B 'custom':45B 'develop':60B 'ide':19B,54B 'idea':22B,27B 'intellij':21B,26B 'intellij-idea':20B 'intern':57B 'java':23B 'jetbrain':24B 'machin':62B 'made':32B 'packag':25B 'plugin':46B 'reach':56B 'repositori':47B 'request':38B 'see':64B 'send':34B 'server':36B 'server-sid':35B 'servic':58B 'set':48B 'side':37B 'use':52B","search_c":"'2026.3':70C 'custom':75C 'idea':68C 'intellij':67C 'jetbrain':66C 'plugin':76C 'possibl':73C 'repositori':77C 'ssrf':71C 'via':74C","first_public_at":"2026-11-06T17:17:23+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","cvss_by":"cve@jetbrains.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123844","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123844","severity":null,"published_at":"2026-11-06T17:17:23+00:00","modified_at":"2026-11-06T17:17:23+00:00","first_seen_at":"2026-11-06T17:43:13+00:00","fetched_at":"2026-11-06T17:43:13+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"}