CyberSecBulletin
CVE-2026-114490NVD status: Awaiting Analysis

hMailServer: Incorrect Authorization

Published Updated By the CyberSecBulletin desk

CVE-2026-114490 is a high-severity incorrect authorization vulnerability in hMailServer from Progressive Robot, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected hMailServer versions: 6.3.4 through 6.3.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.11% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of hMailServer you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
Progressive RobothMailServer6.3.4 through 6.3.6Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (gitlab.com).

Official description

Incorrect authorization in the COM administration API of Progressive Robot hMailServer 6.3.4 through 6.3.6 allows an account assigned the serveradmin role with a list of domains - a credential an administrator may create meaning to confine it to those domains - to act as the whole-server administrator over COM. Administrator roles are meant to confine such a credential to the domains its list names, and the REST API did not take it for the server administrator, but the COM API's server-administrator check read the administer_server permission as the whole server whatever list the grant carried. So the credential signed in through the Control Panel, or through a script run on the server, as the server administrator of every domain: it could read and change every domain's accounts and mail, rename any domain, map a domain alias onto any, write the server's settings and secrets, and create further server-administrator accounts. The COM API's domain-administrator check, asked with no domain, likewise let an account assigned the domainadmin role with a list of domains that leaves out the account's own domain administer that domain's ordinary accounts over COM. An account holding serveradmin with no list is the server administrator by design and is unaffected, as are the help desk, auditor and custom roles.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Incorrect Authorization vulnerabilities (CWE-863)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in hMailServer

All hMailServer vulnerabilities

Recent Incorrect Authorization vulnerabilities

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