High severity · published Mar 11, 2026
CVE-2026-1708
Appointment Booking Calendar <= 1.6.9.27 - Unauthenticated SQL Injection via 'append_where_sql' Parameter
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to blind SQL Injection in all versions up to, and including, 1.6.9.27. This is due to the `db_where_conditions` method in the `TD_DB_Model` class failing to prevent the `append_where_sql` parameter from being passed through JSON request bodies, while only checking for its presence in the `$_REQUEST` superglobal. This makes it possible for unauthenticated attackers to append arbitrary SQL commands to queries and extract sensitive information from the database via the `append_where_sql` parameter in JSON payloads granted they have obtained a valid `public_token` that is inadvertently exposed during the booking flow.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AB
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin · croixhaug
through 1.6.9.27 · source: vendor
Affected product
AB
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin
croixhaug
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-1708
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-1708
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/class-appointment-model.php#L1340
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/class-appointment-model.php#L1413
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/lib/td-util/class-td-db-model.php#L1019
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/lib/td-util/class-td-db-model.php#L1025
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-appointment-model.php#L1340
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-appointment-model.php#L1413
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