Auth bypass in Online Scheduling And Appointment Booking System

CVE-2026-86839

The Online Scheduling and Appointment Booking System WordPress plugin before 28.3 does not verify that appointment and payment records requested through its staff-role AJAX actions belong to the requesting staff member, allowing authenticated attackers with a staff-level account to view, modify and delete other staff members' appointments and payments, including the associated customer's personal information.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.8 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (6.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 6.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-86839: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Online Scheduling And Appointment Booking System

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-86839?
CVE-2026-86839 is a low-severity vulnerability in Online Scheduling And Appointment Booking System, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 3.8/10. Published 2026-09-27.
How severe is CVE-2026-86839?
Low severity. CVSS v3 base score is 3.8 out of 10.