CVE-2026-5465

Amelia <= 2.1.3 - Insecure Direct Object Reference to Authenticated (Employee+) Privilege Escalation via 'externalId' Parameter

2026-04-06 18:13
Osvaldo Noe Gonzalez Del Rio (Os)

Strategic Overview

Status
Patched in 2.2
Affected Plugin
Booking for Appointments and Events Calendar – Amelia
Affected Version
<= 2.1.3
CVSS
8.8High
Weakness type
CWE-639 · Authorization Bypass Through User-Controlled Key
CVE
CVE-2026-5465
View all Booking for Appointments and Events Calendar – Amelia vulnerabilities

At a glance

CVE-2026-5465 is a high-severity Authorization Bypass Through User-Controlled Key vulnerability in the Booking for Appointments and Events Calendar WordPress plugin, affecting versions <= 2.1.3. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Employee level or above. The issue is fixed in version 2.2; sites on affected versions should update now. Disclosed April 2026, reported by Osvaldo Noe Gonzalez Del Rio (Os).

Vulnerability Overview

The Booking for Appointments and Events Calendar – Amelia plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 2.1.3. This is due to the `UpdateProviderCommandHandler` failing to validate changes to the `externalId` field when a Provider (Employee) user updates their own profile. The `externalId` maps directly to a WordPress user ID and is passed to `wp_set_password()` and `wp_update_user()` without authorization checks. This makes it possible for authenticated attackers, with Provider-level (Employee) access and above, to take over any WordPress account — including Administrator — by injecting an arbitrary `externalId` value when updating their own provider profile.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-639: Authorization Bypass Through User-Controlled Key

Booking for Appointments and Events Calendar <= 2.1.3 carries this weakness at wp_set_password(), and reaching it takes an account at Employee level or above. Authorization bypass through a user-controlled key, often called insecure direct object reference, means the application looks up a record by an identifier from the request without checking that the caller owns it.

Changing a number in the request is enough to read or modify other users' records, which on commerce and membership sites means customer data. For Booking for Appointments and Events Calendar the fix is 2.2: builds <= 2.1.3 are affected, anything from 2.2 onward is not.

Remediation

Update to version 2.2, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Booking for Appointments and Events Calendar 2.2 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-5465https://www.wordfence.com/threat-intel/vulnerabilities/id/a4204099-1065-4167-8b42-3da25945236chttps://nvd.nist.gov/vuln/detail/CVE-2026-5465

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C