Medium severity · published Oct 10, 2026
CVE-2026-6723
Appointment Booking Calendar <= 1.6.11.11 - Incorrect Authorization to Unauthenticated Sensitive Field Modification via Appointment Public Token
5.3
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SS
Simply Schedule Appointments · croixhaug
through 1.6.11.11 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6723
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-6723
www.wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/b6f16178-1aa3-4af2-a125-74467bc57e70?source=cve
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/changeset/3562241/simply-schedule-appointments
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