{"id":"CVE-2026-118177","state":"PUBLISHED","title":"Calendar discovery accepted local file and remote network share locations","description":"When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network shares. A malicious server, or a network attacker when the lookup used plain HTTP, could make Thunderbird subscribe to such a location. On Windows this could leak the user's NTLM credentials to an attacker-controlled host on every calendar refresh, and changes to the calendar could be written to the attacker's share or overwrite a local file. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.","publishedAt":"2026-10-27T18:16:31.083Z","updatedAt":"2026-10-27T18:27:49.964Z","severity":null,"assigner":"mozilla","products":["Mozilla Thunderbird"],"affected":[{"vendor":"Mozilla","product":"Thunderbird","versions":[{"version":"153.6","status":"unaffected","lessThanOrEqual":"153.*","versionType":"rpm"},{"version":"159","status":"unaffected","lessThanOrEqual":"*","versionType":"rpm"}]}],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=2080924","https://www.mozilla.org/security/advisories/mfsa2026-121/","https://www.mozilla.org/security/advisories/mfsa2026-122/"],"weaknesses":[],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/118xxx/CVE-2026-118177.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-118177","state":"PUBLISHED","datePublished":"2026-10-27T18:16:31.083Z","dateUpdated":"2026-10-27T18:27:49.964Z","assignerShortName":"mozilla","assignerOrgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","dateReserved":"2026-10-27T18:16:30.717Z"},"containers":{"cna":{"title":"Calendar discovery accepted local file and remote network share locations","descriptions":[{"lang":"en","value":"When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network shares. A malicious server, or a network attacker when the lookup used plain HTTP, could make Thunderbird subscribe to such a location. On Windows this could leak the user's NTLM credentials to an attacker-controlled host on every calendar refresh, and changes to the calendar could be written to the attacker's share or overwrite a local file. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6."}],"affected":[{"vendor":"Mozilla","product":"Thunderbird","versions":[{"version":"153.6","status":"unaffected","lessThanOrEqual":"153.*","versionType":"rpm"},{"version":"159","status":"unaffected","lessThanOrEqual":"*","versionType":"rpm"}]}],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2080924"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-121/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-122/"}],"providerMetadata":{"shortName":"mozilla","orgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","dateUpdated":"2026-10-27T18:27:49.964Z"},"credits":[{"lang":"en","value":"Magnus Melin"}]}}}}