{"id":"MAL-2026-18921","kind":"package","aliases":["MAL-2026-18921"],"related":[],"title":"Malicious code in @yun-xiao/baileys (npm)","description":"@yun-xiao/baileys is a fork of the Baileys WhatsApp Web library that silently subscribes the installer's own WhatsApp account to WhatsApp Channels chosen by the publisher. When the socket connects, code in lib/Socket/newsletter.js sends the WhatsApp w:mex FOLLOW query for the channel ID(s) 120363407049212252@newsletter, 120363425547320365@newsletter, using the victim's authenticated session and without telling them. Same behaviour as the PhantomSub family (MAL-2026-17342).","summary":null,"severity":"critical","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"@yun-xiao/baileys","fixed":[],"affected":"= 2.0.0","ecosystem":"npm"}],"ecosystems":["npm"],"tags":["malicious","package"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-27T00:00:00+00:00","first_seen_at":"2026-11-09T23:37:49+00:00","triaged_at":"2026-11-09T23:39:36+00:00","updated_at":"2026-11-09T23:39:36+00:00","category":"package","confidence":null,"triage":null,"analyst_status":null,"analyst_note":null,"search":"'-17342':91C '-18921':11A,14A '-2026':10A,13A,90C '/baileys':7A,18A,24C '120363407049212252':69C '120363425547320365':71C 'account':42C 'authent':77C 'bailey':30C 'behaviour':84C 'channel':45C,66C 'chosen':46C 'code':2A,54C 'connect':53C 'famili':88C 'follow':62C 'fork':27C 'id':67C 'instal':38C 'lib/socket/newsletter.js':56C 'librari':33C 'mal':9A,12A,89C 'malici':1A,19B 'mex':61C 'newslett':70C,72C 'npm':8A 'packag':20B 'phantomsub':87C 'publish':49C 'queri':63C 'send':57C 'session':78C 'silent':35C 'socket':52C 'subscrib':36C 'tell':81C 'use':73C 'victim':75C 'w':60C 'web':32C 'whatsapp':31C,41C,44C,59C 'without':80C 'xiao':6A,17A,23C 'yun':5A,16A,22C 'yun-xiao':4A,15A,21C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"fix_status":null,"audience":null,"plain_action":null,"pkeys":["baileys"],"ptokens":["baileys","xiao","yun"],"labels":["critical","malicious","npm","package"],"campaign_type":null,"search_a":"'-18921':11A,14A '-2026':10A,13A '/baileys':7A,18A 'code':2A 'mal':9A,12A 'malici':1A 'npm':8A 'xiao':6A,17A 'yun':5A,16A 'yun-xiao':4A,15A","search_b":"'malici':19B 'packag':20B","search_c":"'-17342':91C '-2026':90C '/baileys':24C '120363407049212252':69C '120363425547320365':71C 'account':42C 'authent':77C 'bailey':30C 'behaviour':84C 'channel':45C,66C 'chosen':46C 'code':54C 'connect':53C 'famili':88C 'follow':62C 'fork':27C 'id':67C 'instal':38C 'lib/socket/newsletter.js':56C 'librari':33C 'mal':89C 'mex':61C 'newslett':70C,72C 'phantomsub':87C 'publish':49C 'queri':63C 'send':57C 'session':78C 'silent':35C 'socket':52C 'subscrib':36C 'tell':81C 'use':73C 'victim':75C 'w':60C 'web':32C 'whatsapp':31C,41C,44C,59C 'without':80C 'xiao':23C 'yun':22C 'yun-xiao':21C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-10-27T00:00:00+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"osv-malicious","external_id":"MAL-2026-18921","url":"https://osv.dev/vulnerability/MAL-2026-18921","severity":"critical","published_at":"2026-10-27T00:00:00+00:00","modified_at":"2026-11-09T23:15:16+00:00","first_seen_at":"2026-11-09T23:37:49+00:00","fetched_at":"2026-11-09T23:37:49+00:00","note":null}],"documents":[],"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"}