Progressive Robot hMailServer up to 6.3.6 REST administration API privileges management

Summaryinfo

A vulnerability described as problematic has been identified in Progressive Robot hMailServer up to 6.3.6. This vulnerability affects unknown code of the component REST administration API. Such manipulation leads to privileges management. This vulnerability is documented as CVE-2026-114476. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Progressive Robot hMailServer up to 6.3.6. Affected by this issue is an unknown code block of the component REST administration API. 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. CVE summarizes:

Incorrect authorization in the REST administration API of Progressive Robot hMailServer 6.3.4 through 6.3.6 allows a remote authenticated user whose credential holds the manage_roles permission in named domains - a full-scope API key issued for those domains, or an account assigned the serveradmin role with a list of domains - to obtain the server administrator's authority. An account's admin level gives it authority, and a role assigned to it replaces that authority, which is how an administrator narrows an account whose admin level is the server administrator's. The route that takes a role away (DELETE /api/v1/role-assignments/{address}) checked only that the credential takes in what the account held at the time, not what it would hold afterwards, so such a credential could take a narrowing role away from an account in its domains whose admin level is the server administrator's, returning it to the server administrator's authority, and, having set that account's password while it held the narrower role, sign in as the server administrator.

The advisory is shared for download at gitlab.com. This vulnerability is handled as CVE-2026-114476 since 10/21/2026. The exploitation is known to be easy. The attack may be launched remotely. The exploitation needs additional levels of successful authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/21/2026). The MITRE ATT&CK project declares the attack technique as T1068.

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

• 6.3.0
• 6.3.1
• 6.3.2
• 6.3.3
• 6.3.4
• 6.3.5
• 6.3.6

CPE 2.3info

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CPE 2.2info

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