CVE-2026-6937

Appointment Booking Calendar <= 1.6.11.8 - Missing Authorization to Unauthenticated Arbitrary Modification via Bulk Appointments REST API Endpoint

MEDIUM
5.3
CVSS Score
Published: May 28, 2026 at 07:43 AM UTC
Updated: June 17, 2026 at 11:01 AM UTC
1 product affected across 1 vendorSimply Schedule Appointments

Using Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin by croixhaug?

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 1.6.11.8

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMWordfence
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-862

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