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TI-2026-79993 Aliases CVE-2026-75524

Race condition in OpenReception allows overlapping agent appointments

Priority MEDIUM 58CWE-367Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

OpenReception appointment booking software before 2.2.2 contains a race condition (CWE-367) in which concurrent booking requests can place several appointments into the same exclusive time slot for one agent. A remote attacker with low privileges and one booking token can overbook an agent, because the token is consumed only after the insert. This breaks the integrity of the booking calendar and denies availability to other clients.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00266 18th percentileScored 2026-11-07
Fix Fixed appointment-booking-software (open-reception): 2.2.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
open-receptionappointment-booking-softwarebefore 2.2.22.2.2Patch availableCNA
  • appointment-booking-software Vendoropen-reception Affected before 2.2.2 Fixed in 2.2.2 Patch available CNA

Remediation

Upgrade OpenReception appointment-booking-software to version 2.2.2, which fixes the issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA appointment-booking-software (open-reception) Fixed in 2.2.2

Timeline

  1. 2026-10-23 Threatist record created from CVE-2026-75524
  2. 2026-10-24 Priority changed: MEDIUM → LOW
  3. 2026-10-29 CISA SSVC decision points changed
  4. 2026-10-29 Priority changed: LOW → MEDIUM

References

Other 3

  • TI-2026-35529 OpenReception vulnerable to unauthenticated staff crypto poisoning that breaks E2E recipient directory CVSS 3.1CRITICAL 9.4
  • TI-2026-35528 OpenReception: WebAuthn passkey injection allows account takeover CVSS 3.1CRITICAL 9.8
  • TI-2026-35526 OpenReception has unauthenticated GLOBAL_ADMIN account creation post-bootstrap CVSS 3.1CRITICAL 9.8
  • TI-2026-35527 OpenReception: Tenant admin self-promotes to GLOBAL_ADMIN CVSS 3.1CRITICAL 9.9
  • TI-2026-79990 Host header poisoning in OpenReception enables account takeover CVSS 3.1HIGH 8.3
  • TI-2026-35522 OpenReception vulnerable to stored click-triggered XSS via javascript: tenant links rendered into patient-facing footer CVSS 3.1HIGH 8.1
See all 21 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences