CVE-2026-39587

WP BASE Booking of Appointments, Services and Events <= 5.9.0 - Unauthenticated Privilege Escalation

2026-04-08 00:00
Jarno Vos (jarnovos)

Strategic Overview

Status
Patched in 6.0.0
Affected Version
<= 5.9.0
CVSS
9.8Critical
Weakness type
CWE-269 · Improper Privilege Management
CVE
CVE-2026-39587
View all WP BASE Booking of Appointments, Services and Events vulnerabilities

At a glance

CVE-2026-39587 is a critical-severity Improper Privilege Management vulnerability in the WP BASE Booking of Appointments, Services and Events WordPress plugin, affecting versions <= 5.9.0. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 6.0.0; sites on affected versions should update now. Disclosed April 2026, reported by Jarno Vos (jarnovos).

Vulnerability Overview

The WP BASE Booking of Appointments, Services and Events plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 5.9.0. This makes it possible for unauthenticated attackers to elevate their privileges to that of an administrator.

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 privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-269: Improper Privilege Management

Reaching this weakness in WP BASE Booking of Appointments, Services and Events <= 5.9.0 takes no account at all. Improper privilege management means the code lets an account end up with capabilities its role should not have.

It converts a low-privileged account into an administrative one, which makes every other restriction on the site irrelevant. For WP BASE Booking of Appointments, Services and Events the fix is 6.0.0: builds <= 5.9.0 are affected, anything from 6.0.0 onward is not.

Remediation

Update to version 6.0.0, or a newer patched version

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: WP BASE Booking of Appointments, Services and Events 6.0.0 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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