{"id":"CVE-2026-118177","title":"Calendar discovery accepted local file and remote network share locations","summary":"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…","severity":"none","vendor":"Mozilla","product":"Thunderbird","affected":["Thunderbird"],"published":"2026-10-27","updated":"2026-10-27","sourceUpdated":"2026-10-27T18:27:49.964Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-118177","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/"}],"tags":["cve.org"],"ingestedAt":"2026-10-27T18:52:10.021Z","slug":"CVE-2026-118177","body":"## Overview\n\nWhen 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.\n\n## Affected\n\n- `Thunderbird`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}