CVE-2026-107571 Incorrect Default Permissions in hMailServer
Local attackers can escalate privileges to system level by installing hMailServer in a writable directory, allowing them to replace service binaries.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-107571?
CVE-2026-107571 is a high-severity vulnerability in Progressive Robot Ltd hMailServer, published on 19 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-276
Which versions are affected by CVE-2026-107571?
How do I fix CVE-2026-107571?
No fix has been published for CVE-2026-107571 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-107571 being exploited?
There is no known exploitation of CVE-2026-107571 in the wild and no public exploit code.
Sources
Also known as GHSA-xgwq-m9m9-pgw3.