{"id":"CVE-2026-123311","kind":"vulnerability","aliases":["CVE-2026-123311"],"related":[],"title":"JetBrains IntelliJ IDEA: Markdown preview hidden run control allows command execution","description":"In JetBrains IntelliJ IDEA before 2026.3, \n2026.2.4 command execution via a hidden run control in the Markdown preview was possible","summary":"In JetBrains IntelliJ IDEA before 2026.3 and 2026.2.4, a hidden run control in the Markdown preview allowed command execution. An attacker who gets a developer to open a crafted Markdown file could run commands on that developer's machine.","severity":"medium","cvss":5.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["developer-tools","intellij-idea","jetbrains","markdown","package"],"not_affected_if":["up-to-date-ide"],"how_to_check":"- Open IntelliJ IDEA and check the version under Help > About; compare it with `2026.3` and `2026.2.4`","fix":"- JetBrains IntelliJ IDEA: move to `2026.3` or `2026.2.4`","status":"open","published_at":"2026-11-06T11:17:10+00:00","first_seen_at":"2026-11-06T11:41:26+00:00","triaged_at":"2026-11-06T11:42:35+00:00","updated_at":"2026-11-06T11:42:35+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-11-06T11:42:35Z","model":"claude-haiku-5-5","output":{"fix":"- JetBrains IntelliJ IDEA: move to `2026.3` or `2026.2.4`\n- unknown","reach":"local","title":"JetBrains IntelliJ IDEA: Markdown preview hidden run control allows command execution","impact":"high","summary":"In JetBrains IntelliJ IDEA before 2026.3 and 2026.2.4, a hidden run control in the Markdown preview allowed command execution. An attacker who gets a developer to open a crafted Markdown file could run commands on that developer's machine.","audience":"developers","category":"package","nicknames":[],"who_cares":["intellij-idea","jetbrains","markdown","developer-tools"],"confidence":0.5,"fix_status":"available","needs_auth":"unknown","worst_case":"Commands run on the developer's machine with their user rights","analyst_note":"Confirm affected version ranges and whether the Markdown preview must be open or the file explicitly trusted, from the JetBrains security advisory.","how_to_check":"- Open IntelliJ IDEA and check the version under Help > About; compare it with `2026.3` and `2026.2.4`\n- unknown","plain_action":"","needs_analyst":true,"not_affected_if":["up-to-date-ide"],"who_is_affected":"Anyone running IntelliJ IDEA older than the fixed versions who opens Markdown files, including untrusted ones from repositories or downloads, may be exposed. The sources do not say whether preview must be enabled or whether user interaction is required beyond opening the file.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000702,"input_tokens":4189,"output_tokens":567,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-123311':14A,17A '-2026':13A,16A '2026.2.4':34B,72C '2026.3':32B,71C 'allow':9A,43B 'attack':47B 'command':10A,44B,60B,73C 'control':8A,38B,79C 'could':58B 'craft':55B 'cve':12A,15A 'develop':19B,51B,63B 'developer-tool':18B 'execut':11A,45B,74C 'file':57B 'get':49B 'hidden':6A,36B,77C 'idea':3A,23B,30B,69C 'intellij':2A,22B,29B,68C 'intellij-idea':21B 'jetbrain':1A,24B,28B,67C 'machin':65B 'markdown':4A,25B,41B,56B,82C 'open':53B 'packag':26B 'possibl':85C 'preview':5A,42B,83C 'run':7A,37B,59B,78C 'tool':20B 'via':75C","nicknames":[],"mitigations":[],"who_affected":"Anyone running IntelliJ IDEA older than the fixed versions who opens Markdown files, including untrusted ones from repositories or downloads, may be exposed. The sources do not say whether preview must be enabled or whether user interaction is required beyond opening the file.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["developertools","intellijidea","jetbrains","markdown","medium","package"],"campaign_type":null,"search_a":"'-123311':14A,17A '-2026':13A,16A 'allow':9A 'command':10A 'control':8A 'cve':12A,15A 'execut':11A 'hidden':6A 'idea':3A 'intellij':2A 'jetbrain':1A 'markdown':4A 'preview':5A 'run':7A","search_b":"'2026.2.4':34B '2026.3':32B 'allow':43B 'attack':47B 'command':44B,60B 'control':38B 'could':58B 'craft':55B 'develop':19B,51B,63B 'developer-tool':18B 'execut':45B 'file':57B 'get':49B 'hidden':36B 'idea':23B,30B 'intellij':22B,29B 'intellij-idea':21B 'jetbrain':24B,28B 'machin':65B 'markdown':25B,41B,56B 'open':53B 'packag':26B 'preview':42B 'run':37B,59B 'tool':20B","search_c":"'2026.2.4':72C '2026.3':71C 'command':73C 'control':79C 'execut':74C 'hidden':77C 'idea':69C 'intellij':68C 'jetbrain':67C 'markdown':82C 'possibl':85C 'preview':83C 'run':78C 'via':75C","first_public_at":"2026-11-06T11:17:10+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N","cvss_by":"cve@jetbrains.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123311","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123311","severity":null,"published_at":"2026-11-06T11:17:10+00:00","modified_at":"2026-11-06T11:17:10+00:00","first_seen_at":"2026-11-06T11:41:26+00:00","fetched_at":"2026-11-06T11:41:26+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"}