CVE-2026-100741 (GCVE-0-2026-100741)

Vulnerability from cvelistv5 – Published: 2026-09-27 07:12 – Updated: 2026-09-27 07:12
VLAI
Title
Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') in hMailServer
Summary
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 OnClientValidatePassword handler defined in the event script. The server wrote event values into the handler call as JScript string literals, escaping the apostrophe but not the backslash, so such a value closes the literal and the rest of it is parsed as script. The same flaw is reachable by a remote POP3 server through the message UID it returns, where an OnExternalAccountDownload handler is defined, and by a remote SMTP server through the error reply it rejects a delivery with, where an OnDeliveryFailed handler is defined. Before 6.2.25 the injected script can create any COM object, and from 6.2.25 it can with the default ScriptAllowedObjects value of '*'; WScript.Shell among them gives command execution as the service account. VBScript event scripts and the Linux builds of Progressive Robot Ltd's hMailServer are not affected.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-95 - Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
Assigner
References
Impacted products
Vendor Product Version CPE status
Progressive Robot Ltd hMailServer Affected: 6.0.0 , < 6.3.4 (semver)
guessed Create a notification for this product.
Credits
Found in the hMailServer project's own code review (Progressive Robot Ltd)
Show details on NVD website
To clipboard 

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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.