CVE-2026-104704
HIGH
7,4
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: none
Description
AI Translation Available
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 set consisting of DANE-TA (usage 2) or otherwise unusable records as if no records were published, so delivery to such a host fell back to opportunistic TLS. An attacker with an active position on the network path between the server and the recipient's mail exchanger can suppress or break the STARTTLS negotiation and cause messages to be delivered in cleartext, where they can be read and modified.
319
Cleartext Transmission of Sensitive Information
DraftCommon Consequences
Security Scopes Affected:
Integrity
Confidentiality
Potential Impacts:
Read Application Data
Modify Files Or Directories
Other
Applicable Platforms
Technologies:
Not Technology-Specific, Cloud Computing, Mobile, ICS/OT, System on Chip, Test/Debug Hardware
https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6
https://gitlab.com/hmailserver/hmailserver/-/work_items/61