Threat database

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.

CVE-2026-100741 is a critical eval injection vulnerability in Progressive Robot Ltd's hMailServer versions 6.0.0 through 6.3.3 on Windows. It allows a remote unauthenticated attacker to execute arbitrary JScript code with service account privileges via crafted passwords or certain message fields when event scripting is enabled with JScript and specific event handlers are defined. The vulnerability does not affect VBScript event scripts or Linux builds. Exploitation requires non-default configurations enabling JScript event scripting and relevant handlers.