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

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.

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Published

May 27, 2026

Last Updated

May 27, 2026

Slug

simply-schedule-appointments

Risk Profile

5.3 CVSS Score

Weakness

Missing Authorization

Vector

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

Researchers

winrace

Operational Summary

What the operator needs to know

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Patch Status

Patched release is available

Remediation

Update to version 1.6.11.9, or a newer patched version

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/ef0f5f9d-788a-4cf8-9747-ada076a69a1f?source=api-prod

Detailed Metadata

Software Type	Plugin
Software Slug	simply-schedule-appointments View on wordpress.org
CVE	CVE-2026-6937
Patched Versions	1.6.11.9
Affected Versions	*-1.6.11.8

Licensing Notices

This record contains material that is subject to copyright

DEFIANT

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MITRE

License: CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy. Read more