{"schema":"threatline.record/2","record":{"id":"CVE-2026-114478","aliases":[],"summary":"Unintended Proxy or Intermediary ('Confused Deputy') in hMailServer","details":"Insufficient preservation of the original sender in the forwarding of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have mail they write, naming in its From an address at a domain the server hosts, delivered to other receivers as passing that domain's DMARC policy. When the server sent on a copy of mail that came from outside - an account's forward, a mail rule's forward, a Sieve redirect, a list's copy, or an alias or list expanding to an outside address - it could give the copy an SMTP identity in the organisation of the domain the copy's From names, whatever the message's origin: with the Sender Rewriting Scheme or the rewrite of the envelope sender on forwarding enabled (both off by default), an address at the forwarding domain; for a list, its bounce address; for a message with an empty envelope sender, none, under the server's own host name; and an envelope sender the message came with at a subdomain of a hosted domain was kept. Where that identity's SPF record authorises the server, other receivers' SPF check of the copy passed for a domain aligned with the From, and DMARC passed with it, although the message had not passed DMARC when the server received it. Exploitation needs a forward, redirect, alias or list that carries the hosted domain's mail to an outside address, and one of: SRS or the envelope rewrite enabled; a list whose bounce address is in the domain's organisation; an envelope sender at a subdomain whose SPF record authorises the server; or, for an empty envelope sender, an SPF record that authorises the server under its host name. The DKIM route to the same result is CVE-2026-107567.","categories":["Unclassified"],"product":"hMailServer","vendor":"Progressive Robot Ltd","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-114478","source_modified_at":"2026-10-21T15:12:35.847Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"hMailServer","vendor":"Progressive Robot Ltd","versions":[{"version":"6.0.0","status":"affected","lessThanOrEqual":"6.3.6","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":5.9,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00261,"percentile":0.16929,"score_date":"2026-10-23"},"published_at":"2026-10-21T15:12:35.847Z","modified_at":"2026-10-21T15:12:35.847Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-114478","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T15:12:35.847Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-114478","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://gitlab.com/hmailserver/hmailserver/-/work_items/90"},{"source":"CVE List","url":"https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.7"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-21T15:12:35.847Z","content_hash":"31537ff068d772358a9a7b49aca252306a32ce9baec5aefabea8299ecdf9f88b"}}