Easy!Appointments Vulnerable to Appointments Takeover via Excessive Data Exposure

Exploitation

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

CVSS

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

EPSS

• CVE-2026-55651: 0.23% estimated exploitation activity in the next 30 days; percentile 13.59 (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 An Excessive Data Exposure vulnerability in the customers search endpoint allows an authenticated user to obtain appointment hashes belonging to other users. Using these hashes, an attacker can modify or delete appointments of other providers, resulting in an Appointments Takeover. Details The customers search endpoint exposes excessive information, including appointment hashes, to any authenticated user without proper authorization checks. These hashes uniquely identify appointments that do not belong to the searching user. By reusing the obtained hashes, an attacker can interact with appointment management endpoints, allowing the modification or deletion of third-party appointments. The lack of object-level authorization controls leads to an Appointments Takeover, impacting data confidentiality and integrity. Impact This vulnerability allows an authenticated user to take control of appointments belonging to other users. By obtaining and reusing the exposed hashes, an…

Published by the source

29 Jul 2026, 16:22 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-4vmm-5qvc-w5p7

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-4vmm-5qvc-w5p7

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# Patch Next advisory brief: CVE-2026-55651

Advisory: Easy!Appointments Vulnerable to Appointments Takeover via Excessive Data Exposure
IDs: CVE-2026-55651, GHSA-4vmm-5qvc-w5p7
Record: https://patchnext.com/advisories/cve-2026-55651 (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: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist alextselegidis/easyappointments: affected >= 1.5.2, <= 1.5.2

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## 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-4vmm-5qvc-w5p7 (OSV record GHSA-4vmm-5qvc-w5p7 lists affected ranges: Packagist alextselegidis/easyappointments >=1.5.2 <=1.5.2)
- Verified: https://github.com/advisories/GHSA-4vmm-5qvc-w5p7 (GitHub-reviewed advisory GHSA-4vmm-5qvc-w5p7 lists affected ranges: Packagist alextselegidis/easyappointments >=1.5.2 <=1.5.2)

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