Several vulnerabilities have been discovered in the Dovecot email server. CVE-2020-12100 Receiving mail with deeply nested MIME parts leads to resource exhaustion as Dovecot attempts to parse it. CVE-2020-12673 Dovecot"s NTLM implementation does not correctly check message buffer size, which leads to a crash when reading past allocation. CVE-2020-12674 Dovecot"s RPA mechanism implementation accepts zero-length message, which leads to assert-crash later on.