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Medium 6.7Published Oct 8, 2026

CVE-2026-107578Improper Link Resolution Before File Access ('Link Following') in hMailServer

Updated under an hour ago ()

Does this affect you?

It affects Progressive Robot Ltd hMailServer. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Improper link resolution and external control of file paths in the administrative command-line operations of hMailServer.exe in Progressive Robot hMailServer 6.3.4 and 6.3.5 allow a local attacker who already runs code as the low-privilege service account to escalate privilege. On Windows, operations run with administrator rights by the installer, DBSetup, the Control Panel or an administrator wrote log entries and crash records into the log folder, created, deleted and changed the permissions of the self-signed certificate and private key in the data folder, and rewrote message files in the data folder, all by path in folders the service account (NT SERVICE\hMailServer, the default for new installations since 6.3.4) can modify, following junctions and mount points; and the store-maintenance operations reached files by names taken from the database, which the service account can write, including names outside the data folder. On Linux, the store-maintenance and object-storage operations run as root followed symbolic links the service account (the packaged hmailserver user, which owns the data folder) planted in it, so a root-run operation read, wrote or removed the link's target as root. A local attacker controlling the service account can thereby gain the administrator's (Windows) or root's (Linux) privileges when such an operation is run.

CVSS
6.7 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-59
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitLab
NVD analysis
Deferred
Record last updated
Oct 8, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Progressive Robot Ltd hMailServer
progressive_robot:hmailserver (from the name)
from 6.3.4 before 6.3.6
CNA record

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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