CVE-2026-126612Progressive Robot Ltd hMailServer link following
CVE-2026-126612 is a link following in Progressive Robot Ltd hMailServer, rated high (7.8 on CVSS 3.1).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
The software follows a symbolic link an attacker planted, so it reads or writes a file other than the one it checked.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, with an ordinary user account, and nobody has to click anything.
What an attacker gains
A successful attack can read the data it protects, change data or behaviour and take it offline. In practice, this kind of flaw lets an attacker read or write files outside the folders the service meant to expose.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- No fixed version is listed yet. Find every place Progressive Robot Ltd hMailServer runs, watch the references for a fix, and plan a replacement if it is no longer supported.
- Limit who can run code or sign in on the hosts that run it.
Description from NVD
Improper link resolution in the Windows installer of Progressive Robot hMailServer 6.0.0 through 6.3.7 allows a local authenticated user to run code as the mail server's service account or as an administrator when the path to the program folder passes through a junction, a symbolic link or a mount point that the user controls or that every user may change, such as a junction made at the root of a drive, which takes the root's permissions, or through a folder that every user may rename. Setup installed the programs through any such link without first checking who controls it, or whether a folder above the program folder may be renamed, and the service is registered to run the programs by that path, so the programs are installed where a link another account controls leads, or that account can later make the path lead to a folder it controls; the service, which runs as LocalSystem or as its virtual account, and the programs administrators run from Bin are then started from there. 6.3.7's fix for CVE-2026-107571 does not cover this: its hardening of the program folder, Bin and ControlPanel does not change a folder reached through a link that the administrators do not alone control, and setup does not refuse such a path: it installs through the link and at most reports afterwards that the folders could not be hardened. The default installation under Program Files is not affected.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- File storage the service can read or write. The flaw sits between the application and the file system it can reach.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- Between the application and the file system it can reach. An attacker who crosses it can read or write files outside the folders the service meant to expose.
Questions to answer about your own systems
- Where does Progressive Robot Ltd hMailServer run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.