Format string vulnerability in the emfmultipartencrypted function in mail/em-format.c in Evolution 2.12.3 and earlier allows remote attackers to execute arbitrary code via a crafted encrypted message, as demonstrated using the Version field.
GNOME Evolution before 3.2.3 allows user-assisted remote attackers to read arbitrary files via the attachment parameter to a mailto: URL, which attaches the file to the email.