CVE-2026-114473 Incorrect Authorization in hMailServer
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-114473?
CVE-2026-114473 is a medium-severity vulnerability in Progressive Robot Ltd hMailServer, published on 21 Oct 2026.
Official description
Incorrect authorization in the Sender Rewriting Scheme (SRS) of Progressive Robot hMailServer 6.2.1 through 6.3.6 allows a remote attacker to relay mail through the server to outside addresses. With SRS enabled, the server rewrites the envelope sender of mail it forwards to a signed SRS address at the forwarding domain, and passes a bounce to that address back to the original sender; but it took every message to a valid SRS address, whatever its sender, as delivery to a local recipient, so the relay rules and the SMTP authentication they require were not applied, and the message was delivered to the outside address the SRS address encodes. Anyone holding a valid SRS address of the server, such as the recipient of a forwarded message, could have the server relay mail to the address it encodes for 21 days, and an account holder whose account forwards to an outside mailbox could obtain one for any address. SRS is off by default.
Weakness: CWE-863
Which versions are affected by CVE-2026-114473?
How do I fix CVE-2026-114473?
No fix has been published for CVE-2026-114473 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-114473 being exploited?
There is no known exploitation of CVE-2026-114473 in the wild and no public exploit code.
Sources
Also known as GHSA-mvr2-pg72-p566.