# CVE-2026-114474: Use of Less Trusted Source in hMailServer


- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 21 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-q9cg-xjph-9q7j

## What is CVE-2026-114474?

CVE-2026-114474 is a medium-severity vulnerability in Progressive Robot Ltd hMailServer, published on 21 Oct 2026. 

### Official 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.

Weakness: CWE-348 (Use of Less Trusted Source)

## Which versions are affected by CVE-2026-114474?


## How do I fix CVE-2026-114474?

No fix has been published for CVE-2026-114474 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-114474 being exploited?

There is no known exploitation of CVE-2026-114474 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-114474 and fix it if it is affected.

What it is: CVE-2026-114474 is a medium-severity vulnerability in Progressive Robot Ltd hMailServer, published on 21 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-114474 in the wild and no public exploit code.

Affected product: Progressive Robot Ltd hMailServer. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-114474/ (Markdown: https://insights.sbomify.com/CVE-2026-114474/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-114474
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-114474
- OSV: https://osv.dev/vulnerability/CVE-2026-114474

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-114474/
Summaries are generated and may contain mistakes; the official description above is the record.