CVE-2026-1708

Appointment Booking Calendar <= 1.6.9.27 - Unauthenticated SQL Injection via 'append_where_sql' Parameter

2026-03-10 19:14
d.v4n_s3c

Strategic Overview

Status
Patched in 1.6.9.29
Affected Plugin
Simply Schedule Appointments
Affected Version
<= 1.6.9.27
CVSS
7.5High
Weakness type
CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CVE
CVE-2026-1708
View all Simply Schedule Appointments vulnerabilities

At a glance

CVE-2026-1708 is a high-severity Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in the Simply Schedule Appointments WordPress plugin, affecting versions <= 1.6.9.27. It carries a CVSS score of 7.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires no authentication. The issue is fixed in version 1.6.9.29; sites on affected versions should update now. Disclosed March 2026, reported by d.v4n_s3c.

Vulnerability Overview

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.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

Reaching this weakness in Simply Schedule Appointments <= 1.6.9.27 takes no account at all. SQL injection happens when request data is concatenated into a query instead of being bound as a parameter, letting an attacker change the structure of the statement rather than just its values.

A working injection can read any table the database user can see, which on a WordPress install means user records, password hashes and session or API secrets stored in options. For Simply Schedule Appointments the fix is 1.6.9.29: builds <= 1.6.9.27 are affected, anything from 1.6.9.29 onward is not.

Remediation

Update to version 1.6.9.29, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Simply Schedule Appointments 1.6.9.29 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-1708https://www.wordfence.com/threat-intel/vulnerabilities/id/71642341-9fe0-44a9-88f3-70167dc6ca62https://nvd.nist.gov/vuln/detail/CVE-2026-1708

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C