When processing a message that contains multiple S/MIME signatures, a bug in the MIME processing code caused a null pointer dereference, leading to an unexploitable crash. This vulnerability affects Thunderbird < 68.5.
https://bugzilla.mozilla.org/show_bug.cgi?id=1611105
https://security.gentoo.org/glsa/202003-10
https://usn.ubuntu.com/4328-1/