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Back to active CVEs
Medium · CVSS 5.9CVE-2026-114474

Use of Less Trusted Source in hMailServerCVE-2026-114474

Answer in brief

CVE-2026-114474 records a Medium severity (CVSS 5.9) vulnerability in Use of Less Trusted Source in hMailServer. The current sources do not mark it as known exploited. The current feed maps Progressive Robot Ltd/hMailServer (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 21, 2026Updated Oct 21, 2026Source checked Oct 21, 2026First seen by HOL Oct 21, 2026Material review Oct 21, 2026
Upstream Advisory

Key facts

Risk
Medium · CVSS 5.9
Exploitation
Not marked as known exploited
Affected software
1 mapped package or product
Fix availability
Not reported

Why this deserves its current priority

CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Progressive Robot Ltd/hMailServer (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Progressive Robot Ltd/hMailServergeneric>=6.0.0 <=6.3.6Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Progressive Robot Ltd/hMailServer.
  2. 2Review the reported fix. Source-reported solution: Upgrade to hMailServer 6.3.7, in which a download does not take an address hosted on the server from its From as its envelope sender - it keeps the empty envelope sender, as a download whose From names no address does - and a forward or redirect of it is held to the rule 6.3.7 applies to every copy of mail from outside: it is sent on with an envelope sender, or under a host name, in the organisation of a domain its From names only when the message passed DMARC for that organisation when it arrived, which a download never has. Until then, do not forward or redirect to an outside address the mail of an account that collects an external mailbox where that mail's From can name a domain the server hosts; the spam checks of an external account are off unless they are set, and a download has no DMARC verdict of its own to hold it.

Evidence timeline and material changes

  1. Published upstream

    Oct 21, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Oct 21, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Oct 21, 2026

Sources and claim methodology

  • Source referencegitlab.com
  • Source referencegitlab.com
Upstream source description

Use of a less trusted source for the envelope sender in the external-account download of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have mail they write in the name of a domain the server hosts sent on by the server with an envelope sender at that domain, so that it passes the domain's SPF and DMARC at other receivers. A message the server downloads from an external POP3 or IMAP account has no SMTP envelope of its own, and the server took the address in its From header as its envelope sender, whatever that address was. A forward or redirect of the downloaded message to an outside address then left with that address as its envelope sender, which the Sender Rewriting Scheme leaves alone for a hosted domain, so that the receiver's SPF check passed for the forged domain, aligned even under strict alignment, with no non-default setting, host name record or DMARC policy needed. An attacker needs to know a mailbox elsewhere that an account here collects and forwards to an outside address; an account holder who adds an external account of their own can collect from a server of their own, which matters where SmtpAuthenticatedSenderCheck holds signed-in senders to their own addresses.

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • Incorrect Authorization in hMailServerSame progressive robot ltd/hmailserver package

Record context

Vulnerability class
Missing Auth
EPSS
Not reported
CWE IDs
CWE-348
Source
CVE List V5
Source checked
Oct 21, 2026
References
2 linked sources
Open source record