CVE-2026-107587Improper Certificate Validation in hMailServer
Updated under an hour ago ()
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It affects Progressive Robot Ltd hMailServer. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Improper certificate validation in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote unauthenticated attacker to have S/MIME-encrypted mail that the account later sends to another correspondent also encrypted to the attacker's key. When its recipient opened a signed message, the webmail kept the signer's certificate for encrypting replies whether or not the server found its chain trusted, under the first e-mail address the certificate listed rather than the message's From address, and beside any certificate already held for that address. Encrypted mail later sent from the webmail to that address was encrypted to every certificate held for it, so a holder of the kept certificate's key who obtains a copy of such a message can read it.
- CVSS
- 5.9 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N
- Weakness (CWE)
- CWE-295
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitLab
- NVD analysis
- Deferred
- Record last updated
- Oct 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Progressive Robot Ltd hMailServer progressive_robot:hmailserver (from the name) | from 6.3.2 before 6.3.6 | CNA record |
References
- https://gitlab.com/hmailserver/hmailserver/-/work_items/66
- https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.