Vulnerability · Published Oct 21, 2026 · Assigned by GitLab
CVE-2026-114479Not Failing Securely ('Failing Open') in hMailServer
Medium 5.8
In plain English
A medium-severity security flaw in hMailServer from Progressive Robot Ltd. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).
Official description
Not failing securely in the anti-virus attachment-stripping action of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have a message that the server's virus scanner found infected delivered to the recipient's mailbox unchanged. With virus scanning enabled and its action set to remove attachments and deliver the text (the default action deletes the message), the server keeps one text part of an infected message and replaces every attachment with a note. A message whose single part is not text - a program or an archive sent as the whole message, a message carried whole, a file declared an attachment, or an S/MIME message signed as one part, whose content the recipient's mail client opens - had no part the action could pick out, and was delivered as it arrived, with the content the scanner had found and nothing but a line in the application log to show it. Any sender can write such a message.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Progressive Robot Ltd | hMailServer | 6.0.0 – through 6.3.6 |
Weakness: CWE-636 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N