A use-after-free vulnerability can occur in the chrome event handler when it is freed while still in use. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.Referenceshttps://www.mozilla.org/security/advisories/mfsa2019-13/https://www.mozilla.org/security/advisories/mfsa2019-15/https://www.mozilla.org/security/advisories/mfsa2019-14/https://bugzilla.mozilla.org/show_bug.cgi?id=1536405
