Auth bypass in Online Scheduling And Appointment Booking System

CVE-2026-91847

The Online Scheduling and Appointment Booking System WordPress plugin before 28.2 does not verify that the requester owns the AI booking-assistant conversation named in its unauthenticated conversation actions, allowing any unauthenticated visitor to read another visitor's assistant messages and to inject messages into their in-progress conversation.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.3% 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-2026-91847: 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-2026-91847?
CVE-2026-91847 is a medium-severity vulnerability in Online Scheduling And Appointment Booking System, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.8/10. Published 2026-09-19.
How severe is CVE-2026-91847?
Medium severity. CVSS v3 base score is 4.8 out of 10.