SECURELYN

CVE-2026-100741

Eval injection in the JScript event-script dispatcher in Progressive Robot Ltd's hMailServer, versions 6.0.0 through 6.3.3 on Windows, allows a remote, unauthenticated attacker to run arbitrary JScript inside the hMailServer service process, with the privileges of the service account, via a password containing a backslash followed by an apostrophe, sent in any logon (SMTP AUTH, POP3, IMAP) that names an existing, active account. Exploitation requires a non-default configuration: event scripting enabled (off by default), the script language set to JScript (the default is VBScript), and an OnCl…

Scores

9.8
CVSS 9.8 out of 10, critical severity.
1.7%
EPSS 1.7% chance of exploitation in the next 30 days.

The facts

Published
27 September 2026
Last changed
29 September 2026
NVD status
Awaiting Analysis
Severity
Critical, CVSS 9.8 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
1.7% chance of exploitation activity in the next 30 days (percentile 77).

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References