{"id":"CVE-2026-118178","kind":"vulnerability","aliases":["CVE-2026-118178"],"related":[],"title":"Thunderbird: RSS feed redirect reads local files and leaks NTLM credentials","description":"A remote RSS feed could use the itunes:new-feed-url or newLocation element to permanently change its stored subscription URL to a file: URL. Thunderbird then read that location on every feed update. This allowed a malicious feed, or an attacker able to modify a feed delivered over HTTP, to make Thunderbird read local files and, on Windows, connect to an attacker-controlled network share, which could leak the user's NTLM credentials.\nThe NTLM credential leak only affects Thunderbird on Windows. Other operating systems are affected by the local file read only. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.","summary":"A malicious RSS feed can use the itunes:new-feed-url or newLocation element to permanently change its stored subscription URL to a file: location, so Thunderbird reads that local file on every update. On Windows, the same redirect can point at an attacker-controlled network share and leak the user's NTLM credentials.","severity":"high","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["desktop","package","thunderbird","windows"],"not_affected_if":["no-rss-subscriptions"],"how_to_check":"- Check the installed Thunderbird version with Help > About Thunderbird, or `thunderbird --version` on the command line\n- Review RSS subscriptions for any feed URL beginning with file: or a network share path","fix":"- Update Thunderbird to `159` or `153.6`, or a later release of either line","status":"open","published_at":"2026-10-27T19:17:29+00:00","first_seen_at":"2026-10-27T19:33:18+00:00","triaged_at":"2026-10-27T19:35:05+00:00","updated_at":"2026-10-27T19:35:05+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-27T19:35:05Z","model":"claude-haiku-5-5","output":{"fix":"- Update Thunderbird to `159` or `153.6`, or a later release of either line","reach":"internet","title":"Thunderbird: RSS feed redirect reads local files and leaks NTLM credentials","impact":"medium","summary":"A malicious RSS feed can use the itunes:new-feed-url or newLocation element to permanently change its stored subscription URL to a file: location, so Thunderbird reads that local file on every update. On Windows, the same redirect can point at an attacker-controlled network share and leak the user's NTLM credentials.","category":"package","nicknames":[],"who_cares":["thunderbird","windows","desktop"],"confidence":0.8,"needs_auth":"no","worst_case":"Local files read and NTLM credentials leaked to an attacker share","analyst_note":"","how_to_check":"- Check the installed Thunderbird version with Help > About Thunderbird, or `thunderbird --version` on the command line\n- Review RSS subscriptions for any feed URL beginning with file: or a network share path","needs_analyst":false,"not_affected_if":["no-rss-subscriptions"],"who_is_affected":"Thunderbird users who subscribe to RSS or news feeds, where a remote feed or an attacker able to alter a feed delivered over HTTP can supply the redirect. The NTLM credential leak applies only to Windows installs; other operating systems face the local file read only. Users who do not use RSS feed subscriptions are not exposed through this path.","user_interaction":"unknown","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000613,"input_tokens":3422,"output_tokens":541,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-118178':14A,17A '-2026':13A,16A '153.6':183C '159':180C 'abl':121C 'affect':159C,167C 'allow':114C 'attack':67B,120C,142C 'attacker-control':66B,141C 'chang':39B,95C 'connect':138C 'control':68B,143C 'could':82C,147C 'credenti':11A,77B,153C,156C 'cve':12A,15A 'deliv':126C 'desktop':18B 'element':36B,92C 'everi':55B,110C 'feed':3A,25B,32B,81C,88C,111C,117C,125C 'file':7A,46B,53B,102C,134C,171C 'fix':177C 'http':128C 'itun':29B,85C 'leak':9A,72B,148C,157C 'local':6A,52B,133C,170C 'locat':47B,108C 'make':130C 'malici':23B,116C 'modifi':123C 'network':69B,144C 'new':31B,87C 'new-feed-url':30B,86C 'newloc':35B,91C 'ntlm':10A,76B,152C,155C 'oper':164C 'packag':19B 'perman':38B,94C 'point':63B 'read':5A,50B,106C,132C,172C 'redirect':4A,61B 'remot':79C 'rss':2A,24B,80C 'share':70B,145C 'store':41B,97C 'subscript':42B,98C 'system':165C 'thunderbird':1A,20B,49B,104C,131C,160C,179C,182C 'updat':56B,112C 'url':33B,43B,89C,99C,103C 'use':27B,83C 'user':74B,150C 'vulner':175C 'window':21B,58B,137C,162C","nicknames":[],"mitigations":[],"who_affected":"Thunderbird users who subscribe to RSS or news feeds, where a remote feed or an attacker able to alter a feed delivered over HTTP can supply the redirect. The NTLM credential leak applies only to Windows installs; other operating systems face the local file read only. Users who do not use RSS feed subscriptions are not exposed through this path.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T19:17:29+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-118178","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118178","severity":null,"published_at":"2026-10-27T19:17:29+00:00","modified_at":"2026-10-27T19:17:29+00:00","first_seen_at":"2026-10-27T19:33:18+00:00","fetched_at":"2026-10-27T19:33:18+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}