CVE-2026-107571 Details
Description
Incorrect default permissions in the Windows installer of Progressive Robot hMailServer 6.0.0 through 6.3.6 allow a local authenticated user to run code as the mail server's high-privileged accounts when the product is installed in a folder whose permissions are inherited from a writable parent, such as the root of a drive. The installer places the server's programs in the Bin folder of the program folder and gives neither the program folder nor Bin any permissions of their own, so they inherit the parent's. Under the default location, Program Files, ordinary users receive only read and execute and the configuration is not affected; but the installer accepts any path without warning, and a program folder at the root of an NTFS volume inherits write access for a broad group - Authenticated Users (Modify) on a Windows client, Users (create files and folders) on Windows Server. A local user without administrator rights can then alter or replace the service program, which runs as LocalSystem or as the service's virtual account, or the programs an administrator runs elevated from Bin during setup and maintenance, or place a library in Bin that those programs load in place of the system copy, gaining code execution with those privileges. The default Program Files installation is not affected.
A local privilege escalation vulnerability has been identified in the Windows installer of Progressive Robot hMailServer versions 6.0.0 through 6.3.6. The issue arises from incorrect default permissions that allow a local authenticated user to execute code as high-privileged accounts of the mail server. This vulnerability is present when the product is installed in a directory that inherits permissive rights from a writable parent, such as the root of a drive. Under these conditions, the installer places the server's executable files in the 'Bin' folder of the specified program directory without applying any custom permissions. As a result, these folders inherit the parent's permissions, which can be overly permissive, especially at the root of an NTFS volume on a Windows client or server.
Users are advised to upgrade to hMailServer version 6.3.7, which addresses the vulnerability by applying the correct permissions to the program folder, 'Bin', and 'ControlPanel'. For installations at the root of a drive, follow the steps in the hMailServer documentation to move the installation to a new folder under 'Program Files'.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 19, 2026CISA-ADP
Assessed Oct 20, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.7 | [email protected] | Release NotesVendor |
| https://gitlab.com/hmailserver/hmailserver/-/work_items/78 | [email protected] | Issue TrackingTechnical DescriptionVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-276 | Incorrect Default Permissions | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Progressive Robot hMailServer | >= 6.0.0, <= 6.3.6 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 20, 2026 | CVE Modified | CISA-ADP |
| Oct 19, 2026 | New CVE Received | [email protected] |
Volerion