2018-01-26 Thunderbird 52.6.0 https://www.mozilla.org/en-US/thunderbird/52.6.0/releasenotes/ https://www.mozilla.org/en-US/security/known-vulnerabilities/thunderbird/#thunderbird52.6 未更新 追記 https://www.mozilla.org/en-US/security/advisories/mfsa2018-04/ 追記終わり