PLUGIN SECURITY
Is Simply Schedule Appointments safe?
Unlimited appointments, booking calendars, and notifications. Powerful appointment booking plugin and booking system. Start scheduling for free today!
What this plugin does
- Slug:
simply-schedule-appointments - Author: NSquared
- 50000+ active installs
- 100/100 rating (155 reviews on wordpress.org)
- 4076186 all-time downloads
- On WordPress.org since 2018-05-23
appointment bookingappointmentsbookingbooking systemscheduling
Maintenance status
- Latest known version: 1.6.12.15
- Last updated: 2026-08-18 10:06pm GMT
- Tested up to WordPress: 7.1
- Requires PHP: 7.4+
- Max supported PHP (analyzed): 8.4
Known vulnerabilities
41 known CVEs on file for Simply Schedule Appointments.
| CVE | Vulnerability | Type | Severity | Affected | Fixed in | Published | Status |
|---|---|---|---|---|---|---|---|
| CVE-2026-13358 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.11 | Authorization Bypass Through User-Controlled Key | Medium 6.5 | < 1.6.12.11 | 1.6.12.11 | 2026-08-15 | ✓ fixed in latest |
| CVE-2026-16541 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.17 | Exposure of Sensitive Information to an Unauthorized Actor | Unknown | < 1.6.12.17 | 1.6.12.17 | 2026-08-15 | ⚠ update needed |
| CVE-2026-15254 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.11 | Incorrect Authorization | Unknown | < 1.6.12.11 | 1.6.12.11 | 2026-08-03 | ✓ fixed in latest |
| CVE-2026-16540 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.6 | Incorrect Authorization | Unknown | < 1.6.12.6 | 1.6.12.6 | 2026-08-02 | ✓ fixed in latest |
| CVE-2026-65513 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.11 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | High 7.1 | < 1.6.12.11 | 1.6.12.11 | 2026-07-28 | ✓ fixed in latest |
| CVE-2026-65508 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.11 | Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') | Critical 9.3 | < 1.6.12.11 | 1.6.12.11 | 2026-07-28 | ✓ fixed in latest |
| CVE-2026-57812 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.6 | — | Medium 6.5 | < 1.6.12.6 | 1.6.12.6 | 2026-07-09 | ✓ fixed in latest |
| CVE-2026-59523 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.0 | — | Medium 6.5 | < 1.6.12.0 | 1.6.12.0 | 2026-07-09 | ✓ fixed in latest |
+ 40 more known vulnerabilities
| CVE | Vulnerability | Type | Severity | Affected | Fixed in | Published | Status |
|---|---|---|---|---|---|---|---|
| CVE-2026-57317 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.4 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | High 7.1 | < 1.6.12.4 | 1.6.12.4 | 2026-06-26 | ✓ fixed in latest |
| CVE-2026-39447 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.11.0 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | High 7.1 | < 1.6.11.0 | 1.6.11.0 | 2026-05-28 | ✓ fixed in latest |
| CVE-2026-7797 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.11.9 | Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') | High 7.5 | < 1.6.11.9 | 1.6.11.9 | 2026-05-27 | ✓ fixed in latest |
| CVE-2026-6937 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.11.9 | Missing Authorization | Medium 5.3 | < 1.6.11.9 | 1.6.11.9 | 2026-05-27 | ✓ fixed in latest |
| CVE-2026-7493 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.11.7 | Uncontrolled Resource Consumption | Medium 5.3 | < 1.6.11.7 | 1.6.11.7 | 2026-05-26 | ✓ fixed in latest |
| CVE-2026-4807 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.11 | Missing Authorization | Medium 6.5 | < 1.6.11 | 1.6.11 | 2026-05-06 | ✓ fixed in latest |
| CVE-2026-42384 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.11.2 | Insertion of Sensitive Information Into Sent Data | High 7.5 | < 1.6.11.2 | 1.6.11.2 | 2026-04-27 | ✓ fixed in latest |
| CVE-2026-39493 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.9.29 | Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') | Critical 9.3 | < 1.6.9.29 | 1.6.9.29 | 2026-04-08 | ✓ fixed in latest |
| CVE-2026-39495 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.9.29 | — | High 8.5 | < 1.6.9.29 | 1.6.9.29 | 2026-03-26 | ✓ fixed in latest |
| CVE-2026-39694 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.11.1 | — | Medium 5.3 | < 1.6.11.1 | 1.6.11.1 | 2026-02-26 | ✓ fixed in latest |
| CVE-2025-69315 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.9.17 | Missing Authorization | Medium 6.5 | < 1.6.9.17 | 1.6.9.17 | 2026-01-20 | ✓ fixed in latest |
| CVE-2025-12166 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.9.13 | Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') | High 7.5 | < 1.6.9.13 | 1.6.9.13 | 2026-01-14 | ✓ fixed in latest |
| CVE-2025-11723 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.9.6 | Use of Insufficiently Random Values | Medium 6.5 | < 1.6.9.6 | 1.6.9.6 | 2026-01-05 | ✓ fixed in latest |
| CVE-2025-13754 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.9.17 | Missing Authorization | Medium 5.3 | < 1.6.9.17 | 1.6.9.17 | 2025-12-18 | ✓ fixed in latest |
| CVE-2024-13431 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.8.5 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | Medium 6.1 | < 1.6.8.5 | 1.6.8.5 | 2025-03-06 | ✓ fixed in latest |
| CVE-2024-7877 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.7.55 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | Medium 4.8 | < 1.6.7.55 | 1.6.7.55 | 2024-10-15 | ✓ fixed in latest |
| CVE-2024-7876 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.7.55 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | Medium 4.8 | < 1.6.7.55 | 1.6.7.55 | 2024-10-15 | ✓ fixed in latest |
| CVE-2024-7129 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.7.43 | Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') | High 7.2 | < 1.6.7.43 | 1.6.7.43 | 2024-08-23 | ✓ fixed in latest |
| CVE-2024-4288 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.7.18 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | Medium 5.4 | < 1.6.7.18 | 1.6.7.18 | 2024-05-15 | ✓ fixed in latest |
| CVE-2024-22311 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.6.24 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | High 7.1 | < 1.6.6.24 | 1.6.6.24 | 2024-03-26 | ✓ fixed in latest |
| CVE-2024-2342 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.7.9 | Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') | High 8.8 | < 1.6.7.9 | 1.6.7.9 | 2024-03-20 | ✓ fixed in latest |
| CVE-2024-2341 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.7.9 | Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') | Medium 6.5 | < 1.6.7.9 | 1.6.7.9 | 2024-03-20 | ✓ fixed in latest |
| CVE-2024-1760 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.6.24 | Cross-Site Request Forgery (CSRF) | Medium 4.7 | < 1.6.6.24 | 1.6.6.24 | 2024-03-05 | ✓ fixed in latest |
| CVE-2023-50851 | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.6.1 | Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') | High 7.6 | < 1.6.6.1 | 1.6.6.1 | 2023-12-21 | ✓ fixed in latest |
| CVE-2022-2374 | Simply Schedule Appointments [simply-schedule-appointments] < 1.5.7.7 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | Medium 4.8 | < 1.5.7.7 | 1.5.7.7 | 2022-08-08 | ✓ fixed in latest |
| CVE-2022-2373 | Simply Schedule Appointments [simply-schedule-appointments] < 1.5.7.7 | Missing Authorization | Medium 5.3 | < 1.5.7.7 | 1.5.7.7 | 2022-08-08 | ✓ fixed in latest |
| — | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.8.7 | Improper Control of Generation of Code ('Code Injection') | High 7.3 | < 1.6.8.7 | 1.6.8.7 | 0000-00-00 | ✓ fixed in latest |
| — | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.8.32 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | Medium 6.4 | < 1.6.8.32 | 1.6.8.32 | 0000-00-00 | ✓ fixed in latest |
| — | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.10.2 | — | Unknown | < 1.6.10.2 | 1.6.10.2 | 0000-00-00 | ✓ fixed in latest |
| — | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.10.0 | — | Unknown | < 1.6.10.0 | 1.6.10.0 | 0000-00-00 | ✓ fixed in latest |
| — | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.10.0 | — | Unknown | < 1.6.10.0 | 1.6.10.0 | 0000-00-00 | ✓ fixed in latest |
| — | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.9.29 | — | Unknown | < 1.6.9.29 | 1.6.9.29 | 0000-00-00 | ✓ fixed in latest |
| — | Simply Schedule Appointments [simply-schedule-appointments] < 1.6.12.4 | — | Unknown | < 1.6.12.4 | 1.6.12.4 | 0000-00-00 | ✓ fixed in latest |
| CVE-2025-1119 | Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin < 1.6.8.7 - Unauthenticated Arbitrary Shortcode Execution | — | Unknown | < 1.6.8.7 | 1.6.8.7 | — | ✓ fixed in latest |
| CVE-2025-4667 | Simply Schedule Appointments < 1.6.8.32 - Authenticated (Contributor+) Stored Cross-Site Scripting via Multiple Shortcodes | — | Unknown | < 1.6.8.32 | 1.6.8.32 | — | ✓ fixed in latest |
| CVE-2026-1708 | Appointment Booking Calendar < 1.6.9.29 - Unauthenticated SQL Injection via 'append_where_sql' Parameter | — | Unknown | < 1.6.9.29 | 1.6.9.29 | — | ✓ fixed in latest |
| CVE-2026-3045 | Appointment Booking Calendar < 1.6.10.0 - Missing Authorization to Unauthenticated Sensitive Information Exposure via Settings REST API Endpoint | — | Unknown | < 1.6.10.0 | 1.6.10.0 | — | ✓ fixed in latest |
| CVE-2026-1704 | Appointment Booking Calendar < 1.6.10.0 - Insecure Direct Object Reference to Authenticated (Staff+) Sensitive Information Exposure | — | Unknown | < 1.6.10.0 | 1.6.10.0 | — | ✓ fixed in latest |
| CVE-2026-3658 | Appointment Booking Calendar < 1.6.10.2 - Unauthenticated SQL Injection via 'fields' Parameter | — | Unknown | < 1.6.10.2 | 1.6.10.2 | — | ✓ fixed in latest |
| CVE-2026-13400 | Simply Schedule Appointments < 1.6.12.4 - Unauthenticated Stored XSS via Booking Customer Information | — | Unknown | < 1.6.12.4 | 1.6.12.4 | — | ✓ fixed in latest |
How to fix it
Keep Simply Schedule Appointments updated — 1.6.12.15 is the latest version on wordpress.org, and each CVE above lists the exact release that fixed it ("Fixed in").
This is the plugin's full known vulnerability history, not a scan of any specific installation — run a free scan of your own site to check your exact installed version.
Safer / more established alternatives
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- Online Scheduling and Appointment Booking System – Bookly — 60000+ active installs — 88/100 (575) — max PHP <8.0
- Booking Calendar — 40000+ active installs — 94/100 (653) — max PHP 8.4
- SimplyBook.me – Booking and reservations calendar — 30000+ active installs — 90/100 (17) — max PHP 8.4
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