CVE-2026-118177

published 2026-10-27

CVE-2026-118177: When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations…

Priority P4 28 medium 5.4

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

3 ranges

Vendor	Product	Version range	Fixed in
mozilla	thunderbird	< Thunderbird 159	Thunderbird 159
mozilla	thunderbird	< Thunderbird 153.6	Thunderbird 153.6
mozilla	thunderbird	—	—

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CWE-73