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.
History

Fri, 09 Oct 2026 07:30:00 +0000

Type Values Removed Values Added
First Time appeared Progressive Robot
Progressive Robot hmailserver
Vendors & Products Progressive Robot
Progressive Robot hmailserver

Thu, 08 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 08 Oct 2026 11:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Reliance on Untrusted Inputs in a Security Decision in hMailServer
Weaknesses CWE-807
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitLab

Published: 2026-10-08T10:52:45.630Z

Updated: 2026-10-08T17:35:46.645Z

Reserved: 2026-10-02T07:38:54.248Z

Link: CVE-2026-104658

cve-icon Vulnrichment

Updated: 2026-10-08T17:35:42.287Z

cve-icon NVD

Status : Deferred

Published: 2026-10-08T11:16:43.870

Modified: 2026-10-08T21:02:43.860

Link: CVE-2026-104658

cve-icon Redhat

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