Deserialization in Online Scheduling And Appointment Booking System

CVE-2026-86841

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.

Vulnerability class: Insecure Deserialization

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (13.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 13.0% 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-2026-86841: 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-2026-86841?
CVE-2026-86841 is a medium-severity vulnerability in Online Scheduling And Appointment Booking System, classified under Deserialization of Untrusted Data. CVSS score: 4.7/10. Published 2026-09-27.
How severe is CVE-2026-86841?
Medium severity. CVSS v3 base score is 4.7 out of 10.