CVE-2026-3658
Published: 19 March 2026
Summary
CVE-2026-3658 is a high-severity SQL Injection (CWE-89) vulnerability in Wordpress (inferred from references). Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-3658 is a SQL injection vulnerability affecting the Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin for WordPress in all versions up to and including 1.6.10.0. The flaw occurs via the 'fields' parameter due to insufficient escaping of user-supplied input and lack of sufficient preparation in the existing SQL query, as detailed in the plugin's codebase at locations such as class-appointment-type-model.php line 907, class-td-api-model.php line 140, and class-td-db-model.php line 1171.
Unauthenticated attackers can exploit this vulnerability remotely with low complexity and no privileges required, as indicated by the CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N). Successful exploitation allows attackers to append additional SQL queries to existing ones, enabling extraction of sensitive information from the database, including usernames, email addresses, and password hashes.
Mitigation details are referenced in the WordPress plugin trac changeset 3485143, which addresses the issue, and the Wordfence threat intelligence advisory at the provided URL. Security practitioners should update the plugin to a patched version beyond 1.6.10.0 and review the referenced code changes for implementation specifics.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-13093
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
SQL injection in public-facing WordPress plugin directly enables remote unauthenticated exploitation of public-facing applications to extract DB contents (usernames, emails, password hashes).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the SQL injection vulnerability by requiring validation and escaping of user-supplied 'fields' parameter before inclusion in database queries.
Ensures timely identification, reporting, and remediation of the SQL injection flaw in the WordPress plugin via patching to versions beyond 1.6.10.0.
Complements input validation by restricting the 'fields' parameter to authorized values, blocking unauthorized SQL query appendages.