Easy!Appointments appointments/store and appointments/update allow cross-provider appointment injection — Authorization Bypass

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

3.3 · CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N

EPSS

• CVE-2026-52839: 0.18% estimated exploitation activity in the next 30 days; percentile 7.43 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Easy!Appointments correctly filters 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 idusersprovider 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. --- Root Cause — Step by Step Code Flow Step 1 — Search correctly enforces provider isolation The search endpoint filters out appointments belonging to other providers —…

Published by the source

29 Jul 2026, 16:26 UTC

Last modified by the source

29 Jul 2026, 16:30 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-w8xc-8g92-v77h

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-w8xc-8g92-v77h

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# Patch Next advisory brief: CVE-2026-52839

Advisory: Easy!Appointments appointments/store and appointments/update allow cross-provider appointment injection — Authorization Bypass
IDs: CVE-2026-52839, GHSA-w8xc-8g92-v77h
Record: https://patchnext.com/advisories/cve-2026-52839 (revision 2, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: alextselegidis/easyappointments 1.6.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist alextselegidis/easyappointments: affected <= 1.5.2; fixed in 1.6.0

## Suggested inspection (read-only)
- Packagist alextselegidis/easyappointments: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on alextselegidis/easyappointments.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-w8xc-8g92-v77h (OSV record GHSA-w8xc-8g92-v77h lists affected ranges: Packagist alextselegidis/easyappointments >=0 <1.6.0 (fixed))
- Verified: https://github.com/advisories/GHSA-w8xc-8g92-v77h (GitHub-reviewed advisory GHSA-w8xc-8g92-v77h lists affected ranges: Packagist alextselegidis/easyappointments >=0 <=1.5.2)

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