WordPress security changelog
MEDIUM CVE-2026-6937 Deferred

Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin: A security weakness

Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin is affected by a security weakness. The vulnerable path is reachable without authentication. The resulting impact depends on how the affected component exposes the vulnerable operation. The published affected range is <= 1.6.11.8.

CVE / CNA score 5.3 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin
Plugin slug
simply-schedule-appointments
Affected
<= 1.6.11.8
Safe version
> 1.6.11.8
Published
May 28, 2026
Weakness
CWE-862 — Missing Authorization

This CVE was published May 28, 2026 and is one of 31 known issues for this plugin.

What to do

Update, patch or deactivate.

Update Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin to a release after 1.6.11.8, or disable and remove it until a fixed version is available.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 1.6.11.8 due to the plugin not properly verifying that a user is authorized to perform an action via the bulk appointments REST API endpoint. This makes it possible for unauthenticated attackers to modify arbitrary appointment records including customer PII, payment status, and meeting URL fields, and to expose full customer PII from existing appointment records via the bulk endpoint response. The public nonce is a static, user-independent value present in the HTML source of any page hosting the [ssa_booking] shortcode, meaning any visitor who has viewed such a page can obtain it and target any appointment in the system without authentication.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

Primary and upstream sources