What is CVE-2026-75524?

CVE-2026-75524 is a medium-severity vulnerability in Open-Reception Appointment-Booking-Software, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 5.4/10. Published 2026-10-23.

How severe is CVE-2026-75524?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Vulnerability in Open-Reception Appointment-Booking-Software

CVE-2026-75524

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 2.2.2, an attacker overbooks an agent, placing multiple appointments into a single time slot that the system is designed to keep exclusive. The number of overlapping appointments equals the number of concurrent requests, and one booking token is enough because the token is consumed after the insert. This results in the integrity of the booking-calendar breaking and availability being denied to other clients. This issue has been patched in version 2.2.2.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

Published 2026-10-23.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Open-Reception Appointment-Booking-Software — versions < 2.2.2

Weakness classification (CWE)

CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

References

Frequently asked questions

What is CVE-2026-75524?: CVE-2026-75524 is a medium-severity vulnerability in Open-Reception Appointment-Booking-Software, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 5.4/10. Published 2026-10-23.
How severe is CVE-2026-75524?: Medium severity. CVSS v3 base score is 5.4 out of 10.