CVE-2026-104658
CVSS v3
7.8
HIGH
EPSS Score
—
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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 arbitra
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Published
- 2026-10-08
- Last Modified
- 2026-10-08
Frequently asked questions
What is CVE-2026-104658?
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 arbitra
Is CVE-2026-104658 actively exploited?
Active exploitation of CVE-2026-104658 has not been confirmed.
What is the CVSS score for CVE-2026-104658?
CVE-2026-104658 has a CVSS v3 base score of 7.8 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
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