This update for dovecot23 to 2.3.10 fixes the following issues: Security issues fixed: - CVE-2020-10957: Fixed a crash caused by malformed NOOP commands . - CVE-2020-10958: Fixed a use-after-free when receiving too many newlines . - CVE-2020-10967: Fixed a crash in the lmtp and submission components caused by mails with empty quoted localparts . Non-security issues fixed: - The update to 2.3.10 fixes several bugs. Please refer to https://dovecot.org/doc/NEWS for a complete list of changes.