CVE-2026-104658
Published:October 08, 2026
Updated:October 08, 2026
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.
Affected Packages
https://gitlab.com/hmailserver/hmailserver.git (SCM_GIT):
Affected version(s) >=v6.3.4 <v6.3.6Fix Suggestion:
Update to version v6.3.6Related Resources (2)
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Contact UsCVSS v4
Base Score:
8.5
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.8
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Reliance on Untrusted Inputs in a Security Decision