Booking calendar, Appointment Booking System <= 3.2.36 - Missing Authorization to Unauthenticated Arbitrary Modification via wpdevart_payment AJAX Action
Summary
| CVE | CVE-2026-8840 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-15 03:16:48 UTC |
| Updated | 2026-08-17 20:16:47 UTC |
| Description | The Booking calendar, Appointment Booking System plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 3.2.36. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to mark arbitrary reservations as paid or completed, cancel legitimate payments, auto-approve reservations, and trigger transactional booking emails by writing attacker-supplied payment status and transaction data directly into the payments table. The auto-approval of reservations is only triggered when the 'enable_psuccess_approval' site option is enabled, but payment status manipulation and email dispatch are exploitable regardless of that setting. |
Risk And Classification
Primary CVSS: v3.1 5.3 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS: 0.003150000 probability, percentile 0.241970000 (date 2026-08-18)
Problem Types: CWE-862 | CWE-862 CWE-862 Missing Authorization
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| 3.1 | CNA | DECLARED | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Wpdevart | Booking Calendar Appointment Booking System | affected 3.2.36 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/admin/controllers/Paymen... | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/88409bb0-5cb0-4f63-b8f0-d72f5... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/admin/controllers/Paymen... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/admin/controllers/Paymen... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/booking_calendar.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/admin/controllers/Paymen... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/booking_calendar.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.35/booking_calendar.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/booking-calendar/tags/3.2.36/booking_calendar.php | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Raihan Adi Arba (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-08-14T14:05:28.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.