CVE-2026-107584

Progressive Robot hMailServer 6.0.0 through 6.3.5 fails open when applying DANE RFC 7672 to outbound SMTP delivery. The server's validating DNSSEC resolver treated a TLSA or MX lookup that did not complete no answer, SERVFAIL, a malformed reply, an answer without the requested records and without...

CVE-2026-107584

Progressive Robot hMailServer versions 6.0.0 through 6.3.5 are vulnerable to a fail-open condition when applying DANE (RFC 7672) to outbound SMTP delivery. The root cause is that the server's validating DNSSEC resolver treats incomplete lookups (no answer, SERVFAIL, or malformed replies), records...

CVE-2026-107584 Not Failing Securely ('Failing Open') in hMailServer

Progressive Robot hMailServer 6.0.0 through 6.3.5 fails open when applying DANE RFC 7672 to outbound SMTP delivery. The server's validating DNSSEC resolver treated a TLSA or MX lookup that did not complete no answer, SERVFAIL, a malformed reply, an answer without the requested records and without...

CVE-2026-104704

Progressive Robot hMailServer 6.0.0 through 6.3.5 does not enforce TLS for outbound SMTP delivery to a mail exchanger whose DNSSEC-validated TLSA records contain no DANE-EE usage 3 record, contrary to RFC 7672 section 2.2. The server used only DANE-EE records and treated a validated TLSA record s...

CVE-2026-104704

Progressive Robot hMailServer versions 6.0.0 through 6.3.5 are vulnerable to a flaw where the server fails to enforce TLS for outbound SMTP delivery when DNSSEC-validated TLSA records lack a DANE-EE (usage 3) record. Instead of strictly adhering to RFC 7672, the server treats certain unusable rec...

EUVD-2026-94831

Progressive Robot hMailServer 6.0.0 through 6.3.5 does not enforce TLS for outbound SMTP delivery to a mail exchanger whose DNSSEC-validated TLSA records contain no DANE-EE usage 3 record, contrary to RFC 7672 section 2.2. The server used only DANE-EE records and treated a validated TLSA record s...