High severity · published Mar 19, 2026
CVE-2026-3658
Appointment Booking Calendar <= 1.6.10.0 - Unauthenticated SQL Injection via 'fields' Parameter
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to SQL Injection via the 'fields' parameter in all versions up to, and including, 1.6.10.0 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database, including usernames, email addresses, and password hashes.
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)0.3% · higher than 24% 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 1.6.10.0 · source: vendor
Affected product
AB
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin
croixhaug
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-3658
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-3658
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-appointment-type-model.php#L907
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/lib/td-util/class-td-api-model.php#L140
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/lib/td-util/class-td-db-model.php#L1171
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/changeset/3485143/
www.wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/67c7b9b2-e73f-47fe-aecc-14e998a607c8?source=cve
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