---
id: CVE-2026-86841
title: >-
  The Online Scheduling and Appointment Booking System  WordPress plugin before
  28.3 does not prevent deserialization of untrusted input and does not
  correctly restrict a privileged maintenance feature to administrators,
  allowing users gra…
summary: >-
  The Online Scheduling and Appointment Booking System  WordPress plugin before
  28.3 does not prevent deserialization of untrusted input and does not
  correctly restrict a privileged maintenance feature to administrators,
  allowing users gra…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L'
cwe:
  - CWE-502
product: Online Scheduling and Appointment Booking System
affected:
  - online_scheduling_and_appointment_booking_system >= 23.2 < 28.3
published: '2026-09-27'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T16:38:58.950'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86841'
references:
  - url: 'https://wpscan.com/vulnerability/2150717e-7564-4b29-b2e7-362dd3b480c3/'
    label: contact@wpscan.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-28T00:39:32.339944Z'
ingestedAt: '2026-09-27T06:43:46.830Z'
epss: 0.00222
epssPercentile: 0.12759
---

## Overview

The Online Scheduling and Appointment Booking System  WordPress plugin before 28.3 does not prevent deserialization of untrusted input and does not correctly restrict a privileged maintenance feature to administrators, allowing users granted a custom booking-management capability, which an administrator must explicitly assign, to inject arbitrary PHP objects, overwrite privileged site options, and read stored integration secrets.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.