{"id":"CVE-2026-104704","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-104704","generatedAt":"2026-10-28T02:58:15.666Z","title":"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.","description":"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.","published":"2026-10-08T11:16:44.000Z","lastModified":"2026-10-08T21:02:44.000Z","status":"Deferred","sourceIdentifier":"cve@gitlab.com","cvss":{"version":"3.1","score":7.4,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-319"],"affected":[],"epss":{"score":0.0015,"percentile":0.04129,"date":"2026-10-26","history":[{"date":"2026-10-09","score":0.0015,"percentile":0.03684}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-08T11:16:44.000Z","detail":{"score":"7.4","severity":"HIGH","publishedAt":"2026-10-08T11:16:44.457Z"},"summary":"New CVE, high severity (CVSS 7.4)."}],"references":[{"url":"https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6","source":"cve@gitlab.com"},{"url":"https://gitlab.com/hmailserver/hmailserver/-/work_items/61","source":"cve@gitlab.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-104704","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}