CVE-2026-104658: high-severity vulnerability in Progressive Robot Ltd hMailServer
Reliance on Untrusted Inputs in a Security Decision in hMailServer
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.8epss 0.1%
The Linux live-update apply helper (hmailserver-update) of Progressive Robot hMailServer 6.3.4 and 6.3.5 runs as root on a request file written by the unprivileged hmailserver service account, and took from that request the program used to verify an AppImage update's signature and the systemd unit to stop before reading the service account's files. An attacker who already runs code as the hmailserver service account, for example through another flaw in the mail server, can therefore have arbitrary code executed as root, on any Linux installation where the live update's path unit is active - the default for the project's .deb and .rpm packages - and on AppImage installations run under that unit.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
Progressive Robot Ltd · hMailServerRelated CVEs — Progressive Robot Ltd hMailServer
In the same product, most dangerous first.
CVE-2026-100741CRITICALImproper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') in hMailServerEPSS 1.7%CVE-2026-107585MEDIUMAllocation of Resources Without Limits or Throttling in hMailServerEPSS 0.4%CVE-2026-107576HIGHInefficient Algorithmic Complexity in hMailServerEPSS 0.4%CVE-2026-107577HIGHLoop with Unreachable Exit Condition ('Infinite Loop') in hMailServerEPSS 0.4%CVE-2026-107574HIGHInefficient Algorithmic Complexity in hMailServerEPSS 0.4%CVE-2026-107575MEDIUMInefficient Algorithmic Complexity in hMailServerEPSS 0.4%