Answer in brief
CVE-2026-8840 records a Unknown severity vulnerability in Booking calendar, Appointment Booking System <= 3.2.36 - Missing Authorization to Unauthenticated Arbitrary Modification via wpdevart_payment AJAX Action. The current sources do not mark it as known exploited. The current feed maps wpdevart/Booking calendar, Appointment Booking System (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-8840 records a Unknown severity vulnerability in Booking calendar, Appointment Booking System <= 3.2.36 - Missing Authorization to Unauthenticated Arbitrary Modification via wpdevart_payment AJAX Action. The current sources do not mark it as known exploited. The current feed maps wpdevart/Booking calendar, Appointment Booking System (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps wpdevart/Booking calendar, Appointment Booking System (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| wpdevart/Booking calendar, Appointment Booking Systemgeneric | 0 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps wpdevart/Booking calendar, Appointment Booking System (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| wpdevart/Booking calendar, Appointment Booking Systemgeneric | 0 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.