{"id":"CVE-2026-126134","kind":"vulnerability","aliases":["CVE-2026-126134"],"related":[],"title":"Thunderbird on Windows leaks NTLM credentials via feed file share URLs","description":"Thunderbird allowed feed subscriptions to file: URLs that point to a network share. If a user was tricked into subscribing to such a URL, Thunderbird connected to the attacker's server when fetching the feed. Windows then sent the user's NTLM credentials to that server.\nThis bug only affects Thunderbird on Windows. Other operating systems are unaffected. This vulnerability was fixed in Thunderbird 160.","summary":"Thunderbird accepted feed subscriptions pointing to file: URLs on network shares. When a user is tricked into subscribing, Windows sends the user's NTLM credentials to the attacker's server.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["package","thunderbird","windows"],"not_affected_if":["feed-subscriptions-unused","non-windows"],"how_to_check":"- Check the installed Thunderbird version (Help > About Thunderbird) and compare it with the fixed version below.\n- Only Windows installs are affected; `unknown` whether other checks apply.","fix":"- Thunderbird: `160`","status":"open","published_at":"2026-11-10T19:21:14+00:00","first_seen_at":"2026-11-10T19:25:15+00:00","triaged_at":"2026-11-10T20:04:48+00:00","updated_at":"2026-11-10T20:04:48+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-10T20:04:48Z","model":"claude-haiku-5-5","output":{"fix":"- Thunderbird: `160`","reach":"network","title":"Thunderbird on Windows leaks NTLM credentials via feed file share URLs","impact":"medium","summary":"Thunderbird accepted feed subscriptions pointing to file: URLs on network shares. When a user is tricked into subscribing, Windows sends the user's NTLM credentials to the attacker's server.","audience":"everyone","category":"package","nicknames":[],"who_cares":["thunderbird","windows"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"NTLM credentials are sent to an attacker's server","analyst_note":"","how_to_check":"- Check the installed Thunderbird version (Help > About Thunderbird) and compare it with the fixed version below.\n- Only Windows installs are affected; `unknown` whether other checks apply.","plain_action":"Update Thunderbird to version 160 on your Windows computer through its built-in update check.","product_name":"","needs_analyst":false,"not_affected_if":["non-windows","feed-subscriptions-unused"],"who_is_affected":"Only Thunderbird on Windows is affected. Exposure requires a user to subscribe to a malicious feed URL that points to an attacker-controlled network share; other operating systems are unaffected.","user_interaction":"yes","product_ecosystem":"","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000699,"input_tokens":4576,"output_tokens":482,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-126134':14A,17A '-2026':13A,16A '160':115C 'accept':22B 'affect':100C 'allow':52C 'attack':48B,79C 'bug':98C 'connect':76C 'credenti':6A,45B,93C 'cve':12A,15A 'feed':8A,23B,53C,85C 'fetch':83C 'file':9A,27B,56C 'fix':112C 'leak':4A 'network':30B,62C 'ntlm':5A,44B,92C 'oper':105C 'packag':18B 'point':25B,59C 'send':40B 'sent':88C 'server':50B,81C,96C 'share':10A,31B,63C 'subscrib':38B,70C 'subscript':24B,54C 'system':106C 'thunderbird':1A,19B,21B,51C,75C,101C,114C 'trick':36B,68C 'unaffect':108C 'url':11A,28B,57C,74C 'user':34B,42B,66C,90C 'via':7A 'vulner':110C 'window':3A,20B,39B,86C,103C","nicknames":[],"mitigations":[],"who_affected":"Only Thunderbird on Windows is affected. Exposure requires a user to subscribe to a malicious feed URL that points to an attacker-controlled network share; other operating systems are unaffected.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"everyone","plain_action":"Update Thunderbird to version 160 on your Windows computer through its built-in update check.","pkeys":[],"ptokens":[],"labels":["medium","package","thunderbird","windows"],"campaign_type":null,"search_a":"'-126134':14A,17A '-2026':13A,16A 'credenti':6A 'cve':12A,15A 'feed':8A 'file':9A 'leak':4A 'ntlm':5A 'share':10A 'thunderbird':1A 'url':11A 'via':7A 'window':3A","search_b":"'accept':22B 'attack':48B 'credenti':45B 'feed':23B 'file':27B 'network':30B 'ntlm':44B 'packag':18B 'point':25B 'send':40B 'server':50B 'share':31B 'subscrib':38B 'subscript':24B 'thunderbird':19B,21B 'trick':36B 'url':28B 'user':34B,42B 'window':20B,39B","search_c":"'160':115C 'affect':100C 'allow':52C 'attack':79C 'bug':98C 'connect':76C 'credenti':93C 'feed':53C,85C 'fetch':83C 'file':56C 'fix':112C 'network':62C 'ntlm':92C 'oper':105C 'point':59C 'sent':88C 'server':81C,96C 'share':63C 'subscrib':70C 'subscript':54C 'system':106C 'thunderbird':51C,75C,101C,114C 'trick':68C 'unaffect':108C 'url':57C,74C 'user':66C,90C 'vulner':110C 'window':86C,103C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:21:14+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-126134","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126134","severity":null,"published_at":"2026-11-10T19:21:14+00:00","modified_at":"2026-11-10T19:21:14+00:00","first_seen_at":"2026-11-10T19:25:15+00:00","fetched_at":"2026-11-10T19:25:15+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"}