CVE-2026-52839 Easy!Appointments appointments/store and appointments/update allow cross-provider appointment injection — Authorization Bypass
Authenticated providers can inject or reassign appointments to other providers' schedules due to missing ownership checks in mutation endpoints.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-52839?
CVE-2026-52839 is a low-severity missing authorization vulnerability in alextselegidis easyappointments, published on 14 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-52839?
2 open source packages ship an affected version, including alextselegidis/easyappointments.
| Package | Affected | Fixed in |
|---|---|---|
alextselegidis/easyappointments Packagist | All versions | 1.6.0 |
alextselegidis/easyappointments Packagist | All versions | 1.6.0 |
How do I fix CVE-2026-52839?
Upgrade alextselegidis/easyappointments to 1.6.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-52839 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52839 exists.
Sources
Also known as GHSA-w8xc-8g92-v77h.