3.3
LOW CVSS 3.1
CVE-2026-52839
Easy!Appointments appointments/store and appointments/update allow cross-provider appointment injection — Authorization Bypass
Description

Easy!Appointments is a self hosted appointment scheduler. Versions prior to 1.6.0 correctly filter provider-scoped appointments in the `appointments/search` response, proving that provider isolation is an intended security boundary. However, the direct mutation endpoints `appointments/store` and `appointments/update` only check generic appointment privileges and never verify that the submitted `id_users_provider` belongs to the current session. A normal authenticated provider can inject new appointments into another provider's schedule via `store`, or reassign existing appointments into a foreign provider's calendar via `update`. The `store` path contains an additional write-before-crash bug: the unauthorized row is committed to the database before the controller crashes on a type error, so the attacker receives an error response while the foreign appointment is already persisted. Version 1.6.0 patches the issue.

INFO

Published Date :

July 14, 2026, 4:17 p.m.

Last Modified :

July 29, 2026, 5:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-52839 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Easyappointments easy\!appointments
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 LOW [email protected]
Solution
Update Easy!Appointments to version 1.6.0 or later to fix authorization issues.
  • Update Easy!Appointments to version 1.6.0 or later.
  • Verify that appointment records are properly scoped.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-52839 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-52839 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-52839 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-52839 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Jul. 29, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/alextselegidis/easyappointments/commit/725eafa647308846ce887657db12771a829e42ef
    Removed Reference https://github.com/alextselegidis/easyappointments/commit/4abb10545d83ac1a57d03f6502376ee67696ea7c
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 15, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-w8xc-8g92-v77h
    Added SSVC {'id': 'CVE-2026-52839', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-15T14:48:44.724792Z'}
  • New CVE Received by [email protected]

    Jul. 14, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'alextselegidis', 'product': 'easyappointments', 'versions': [{'status': 'affected', 'version': '< 1.6.0'}]}]
    Added Description Easy!Appointments is a self hosted appointment scheduler. Versions prior to 1.6.0 correctly filter provider-scoped appointments in the `appointments/search` response, proving that provider isolation is an intended security boundary. However, the direct mutation endpoints `appointments/store` and `appointments/update` only check generic appointment privileges and never verify that the submitted `id_users_provider` belongs to the current session. A normal authenticated provider can inject new appointments into another provider's schedule via `store`, or reassign existing appointments into a foreign provider's calendar via `update`. The `store` path contains an additional write-before-crash bug: the unauthorized row is committed to the database before the controller crashes on a type error, so the attacker receives an error response while the foreign appointment is already persisted. Version 1.6.0 patches the issue.
    Added CVSS V3.1 AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N
    Added CWE CWE-639
    Added CWE CWE-862
    Added Reference https://github.com/alextselegidis/easyappointments/commit/4abb10545d83ac1a57d03f6502376ee67696ea7c
    Added Reference https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-w8xc-8g92-v77h
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.