CVE-2026-126607: Uncontrolled Search Path Element in hMailServer
Progressive Robot Ltd · hMailServer
Vendor fix available · Affected: Progressive Robot Ltd hMailServer · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 6% of scored CVEs
DescriptionCVE.org
Progressive Robot hMailServer 6.2.3 through 6.3.7 on Windows, with a MySQL or MariaDB database, hands the bundled MariaDB Connector/C the folder of its authentication plugins (the plugin folder in the installation's Bin folder) as Latin-1 bytes, which the client reads in the system's ANSI code page when it builds a plugin's path and loads the plugin with LoadLibraryExA, which allows a local authenticated user to execute code as the hMailServer service's account (LocalSystem, or the service's virtual account for a new installation from 6.3.4) by creating the folder those bytes name in the code page and placing in it a DLL with a plugin's name, when the installation folder's path holds a character between U+0080 and U+00FF whose byte the code page reads as another character, and none above U+00FF, and the user can create that other folder (by default any authenticated user may create a folder directly under the root of the system drive). The server converted the path with the C runtime's wcstombs_s in the C locale, which writes each character up to U+00FF as the byte of the same value: on code page 1252 those bytes are the same letters, while on another code page, such as 1251, or on a UTF-8 code page, they name another folder. The client loads the plugin the database server names in its greeting, unless it is built in, and any plugin the server names in an authentication switch, and tries again at each connection while a load fails, so with a MySQL 8.0 or later server, whose greeting names caching_sha2_password by default, the DLL is loaded at the next connection the service makes, whatever plugin the database account uses; a DLL's entry point runs when it is loaded.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Progressive Robot Ltd · hMailServerfrom 6.2.3 up to and including 6.3.7
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- Progressive Robot Ltd
- Published
- November 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-126607 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.