Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.27% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-114489High confidence
Missing Authorization in hMailServer
Progressive Robot Ltd · hMailServer
8.1HighCVSS 3.1
Within 7 days
Patch availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Progressive Robot Ltd hMailServer and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
Missing authorization in the REST and COM administration APIs of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote authenticated user whose credential is confined to named domains to change mail routing and domain configuration beyond those domains on a multi-tenant server. A domain administrator, an account or API key given another role that manages accounts in named domains, or a full-scope API key issued for named domains could create a domain alias for any name (so that other tenants' mail for that name is diverted to an address the attacker controls, or denied), rename a domain to any name the server does not host, set a rule's bind-to-address, send-using-route or script-function action to reach one of the server's own addresses, a configured route's stored credentials or a function of the server's event script, and set the domain's relay host - which delivery then connects to with no address rule - to an address on the server's own network; and over the COM API any account could set the three rule actions on its own rules, where the script-function action runs at delivery. The authorization gate did not refuse these routes to a confined credential and the handlers were not given the caller; over COM the domain-alias save performed no authorization check at all, the domain rename required only a domain administrator, and a rule save required at most that the caller could change the rule's owner.
What
Missing authorization in the REST and COM administration APIs of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote authenticated user whose credential is confined to named domains to change mail routing and domain configuration beyond those domains on a multi-tenant server. A domain administrator, an account or API key given another role that manages accounts in named domains, or a full-scope API key issued for named domains could create a domain alias for any name (so that other tenants' mail for that name is diverted to an address the attacker controls, or denied), rename a domain to any name the server does not host, set a rule's bind-to-address, send-using-route or script-function action to reach one of the server's own addresses, a configured route's stored credentials or a function of the server's event script, and set the domain's relay host - which delivery then connects to with no address rule - to an address on the server's own network; and over the COM API any account could set the three rule actions on its own rules, where the script-function action runs at delivery. The authorization gate did not refuse these routes to a confined credential and the handlers were not given the caller; over COM the domain-alias save performed no authorization check at all, the domain rename required only a domain administrator, and a rule save required at most that the caller could change the rule's owner.
Why
The application reaches a protected operation without first confirming that the requester is authorised.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Missing authorization in the REST and COM administration APIs of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote authenticated user whose credential is confined to named domains to change mail routing and domain configuration beyond those domains on a multi-tenant server. A domain administrator, an account or API key given another role that manages accounts in named domains, or a full-scope API key issued for named domains could create a domain alias for any name (so that other tenants' mail for that name is diverted to an address the attacker controls, or denied), rename a domain to any name the server does not host, set a rule's bind-to-address, send-using-route or script-function action to reach one of the server's own addresses, a configured route's stored credentials or a function of the server's event script, and set the domain's relay host - which delivery then connects to with no address rule - to an address on the server's own network; and over the COM API any account could set the three rule actions on its own rules, where the script-function action runs at delivery. The authorization gate did not refuse these routes to a confined credential and the handlers were not given the caller; over COM the domain-alias save performed no authorization check at all, the domain rename required only a domain administrator, and a rule save required at most that the caller could change the rule's owner.
Why
The application reaches a protected operation without first confirming that the requester is authorised.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Missing Authorization → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-862 ↗
CWE-862: Missing Authorization. The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- hMailServer: 6.0.0 ≤ 6.3.6
- Fixed
- Upgrade to hMailServer 6.3.7, which refuses the domain-alias create, the domain rename and an internal relay host to a credential that is confined to named domains, and the reaching rule actions (bind-to-address, send-using-route, script-function on an owned rule) to anyone but the server administrator, over both the REST and the COM APIs, while keeping the changes that stay inside the credential's domains. Until then, on a multi-tenant server, do not give a domain-administrator credential, a role that manages accounts in named domains, or a named-domain API key to a party not trusted with the whole server
- keep the REST API off (RestApiPort=0, the default) where it is not needed
- and review existing domain aliases, domain names, relay hosts and account/domain rule actions for entries a confined credential should not have made, and the accounts' own rules for these three actions, which withholding such credentials does not stop an account setting on its own rules over COM (do this after upgrading as well, since an upgrade does not undo a change already made).
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 21 Oct 2026 · Last source change 21 Oct 2026, 15:34 UTC · CWE-862 · Missing Authorization
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-10-22
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-107328
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-107328 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-107328"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.