Dovecot has been updated to fix several security issues.
Sending malformed NOOP command causes crash in submission, submission-login or lmtp service (CVE-2020-10957).
Sending command followed by sufficient number of newlines triggers a use-after-free bug that might crash submission-login, submission or lmtp service (CVE-2020-10958).
Sending mail with empty quoted localpart causes submission or lmtp component to crash (CVE-2020-10967).