Progressive Robot hMailServer 6.3.7 Installer privileges management

Summaryinfo

A vulnerability marked as critical has been reported in Progressive Robot hMailServer 6.3.7. This impacts an unknown function of the component Installer. The manipulation leads to privileges management. This vulnerability is traded as CVE-2026-126622. An attack has to be approached locally. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Progressive Robot hMailServer 6.3.7. This issue affects an unknown code of the component Installer. The manipulation with an unknown input leads to a privileges management vulnerability. Using CWE to declare the problem leads to CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Incorrect default permissions in the Windows installer of Progressive Robot hMailServer 6.3.7 allow a local authenticated user to run code as the administrator who runs setup, when the server is installed into a program folder that is already there and that accounts other than the administrators could write, such as a folder made beforehand at the root of a drive, or when such an installation is upgraded or repaired. 6.3.7 fixed CVE-2026-107571 by giving the program folder, Bin and ControlPanel permissions that only administrators may change, but for a folder that is already there it does so only at the end of setup: setup first copies the programs into Bin, which every user may still write, and runs programs from Bin with the administrator's elevated rights, registering the service among them, before that hardening, so that a library another account places in Bin meanwhile is loaded in place of the system's. A handle an account opened on such a folder while it could write it keeps that access after the hardening. The default installation under Program Files, whose folders give ordinary users read and execute only, is not affected.

It is possible to read the advisory at gitlab.com. The identification of this vulnerability is CVE-2026-126622 since 11/11/2026. The exploitation is known to be easy. Attacking locally is a requirement. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Mail Server Software

Vendor

• Progressive Robot

Name

• hMailServer

Version

• 6.3.7

CPE 2.3info

• 🔒

CPE 2.2info

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