Melograno Booking for Appointments and Events Calendar Plugin Customer Update Endpoint privileges management

Summaryinfo

A vulnerability marked as critical has been reported in Melograno Booking for Appointments and Events Calendar Plugin up to 9.6.2. Affected by this issue is some unknown functionality of the component Customer Update Endpoint. The manipulation of the argument type/externalId leads to privileges management. This vulnerability is listed as CVE-2026-9055. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Melograno Booking for Appointments and Events Calendar Plugin up to 9.6.2 and classified as critical. This issue affects an unknown code of the component Customer Update Endpoint. The manipulation of the argument type/externalId 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. The summary by CVE is:

The Booking for Appointments and Events Calendar – Amelia (Premium) plugin for WordPress is vulnerable to Privilege Escalation in versions 8.0 - 9.6.2. This is due to insufficient validation of the attacker-controlled 'type' parameter in the customer update endpoint, which allows customers to set their role to 'manager' and trigger creation of a WordPress user with the wpamelia-manager role when the 'externalId' parameter is set to 0. This makes it possible for unauthenticated attackers to escalate their privileges to administrator by first elevating to the manager role, then creating a provider entity linked to an administrator user ID and overwriting that administrator's password.

It is possible to read the advisory at wordfence.com. The identification of this vulnerability is CVE-2026-9055 since 05/20/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/02/2026). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

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

• WordPress Plugin

Vendor

• Melograno

Name

• Booking for Appointments and Events Calendar Plugin

Version

• 9.6.0
• 9.6.1
• 9.6.2

CPE 2.3info

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CPE 2.2info

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