{"id":"CVE-2026-126133","published":"2026-11-10T19:21:13.983","lastModified":"2026-11-10T21:19:27.670","description":"When a CalDAV or ICS calendar was accessed through an HTTP proxy that requested authentication, Thunderbird could answer the proxy with the calendar server's username and password. This affected both setting up a new calendar and syncing existing calendars, where a saved password could be sent without any user interaction. A malicious or compromised proxy could use this to obtain the calendar credentials, even for calendars served over HTTPS. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2083485","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-128/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-129/","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}