{"id":"MAL-2026-19044","kind":"package","aliases":["MAL-2026-19044"],"related":[],"title":"Malicious code in yuuki-baileys (npm)","description":"yuuki-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 Yuuki-baileys/lib/Socket/newsletter.js, lib/Socket/newsletter.js sends the WhatsApp w:mex FOLLOW query for the channel ID(s) 120363406005175144@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":"yuuki-baileys","fixed":[],"affected":"= 1.0.1; = 2.0.0; = 2.1.0","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":"2026-11-09T23:38:07+00:00","triaged_at":"2026-11-09T23:45:47+00:00","updated_at":"2026-11-09T23:45:47+00:00","category":"package","confidence":null,"triage":null,"analyst_status":null,"analyst_note":null,"search":"'-17342':90C '-19044':10A,13A '-2026':9A,12A,89C '/lib/socket/newsletter.js':56C '120363406005175144':70C 'account':39C 'authent':76C 'bailey':6A,21C,27C,55C 'baileys':16A 'behaviour':83C 'channel':42C,67C 'chosen':43C 'code':2A,51C 'connect':50C 'famili':87C 'follow':63C 'fork':24C 'id':68C 'instal':35C 'lib/socket/newsletter.js':57C 'librari':30C 'mal':8A,11A,88C 'malici':1A,17B 'mex':62C 'newslett':71C 'npm':7A 'packag':18B 'phantomsub':86C 'publish':46C 'queri':64C 'send':58C 'session':77C 'silent':32C 'socket':49C 'subscrib':33C 'tell':80C 'use':72C 'victim':74C 'w':61C 'web':29C 'whatsapp':28C,38C,41C,60C 'without':79C 'yuuki':5A,15A,20C,54C 'yuuki-bailey':4A,19C,53C 'yuuki-baileys':14A","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"fix_status":null,"audience":null,"plain_action":null,"pkeys":["yuukibaileys"],"ptokens":["baileys","yuuki"],"labels":["critical","malicious","npm","package"],"campaign_type":null,"search_a":"'-19044':10A,13A '-2026':9A,12A 'bailey':6A 'baileys':16A 'code':2A 'mal':8A,11A 'malici':1A 'npm':7A 'yuuki':5A,15A 'yuuki-bailey':4A 'yuuki-baileys':14A","search_b":"'malici':17B 'packag':18B","search_c":"'-17342':90C '-2026':89C '/lib/socket/newsletter.js':56C '120363406005175144':70C 'account':39C 'authent':76C 'bailey':21C,27C,55C 'behaviour':83C 'channel':42C,67C 'chosen':43C 'code':51C 'connect':50C 'famili':87C 'follow':63C 'fork':24C 'id':68C 'instal':35C 'lib/socket/newsletter.js':57C 'librari':30C 'mal':88C 'mex':62C 'newslett':71C 'phantomsub':86C 'publish':46C 'queri':64C 'send':58C 'session':77C 'silent':32C 'socket':49C 'subscrib':33C 'tell':80C 'use':72C 'victim':74C 'w':61C 'web':29C 'whatsapp':28C,38C,41C,60C 'without':79C 'yuuki':20C,54C 'yuuki-bailey':19C,53C","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-2026-19044","url":"https://osv.dev/vulnerability/MAL-2026-19044","severity":"critical","published_at":"2026-10-27T00:00:00+00:00","modified_at":"2026-11-09T23:15:37+00:00","first_seen_at":"2026-11-09T23:38:07+00:00","fetched_at":"2026-11-09T23:38:07+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"}