SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-104658

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…

HIGH 7.8EPSS 0.11%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.11% probability · 2th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-807
Source
cve@gitlab.com
EPSS trend
0%3%5%9 October 2026: 0.11%26 October 2026: 0.11%9 October 202626 October 2026

EPSS moved from 0.1% on 9 October 2026 to 0.1% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.