CVE-2026-52840
Easy!Appointments has server-side request forgery in CalDAV connection test that exposes the deployment's internal network
Description
Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, `Caldav::connect_to_server` at `application/controllers/Caldav.php:60` hands the request's `caldav_url` to a Guzzle `REPORT` call without scheme or host validation. A logged-in backend user (admin, provider, or secretary) reaches loopback, RFC1918, and link-local hosts on the deployment's network. The Guzzle exception path returns the upstream status code plus ~120 bytes of response body in the JSON `message` field (`Caldav.php:74-78`), so the SSRF is semi-blind. Version 1.6.0 contains a patch.
INFO
Published Date :
July 14, 2026, 4:17 p.m.
Last Modified :
July 15, 2026, 2:18 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| 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.
- Apply vendor patch for security.
- Validate all external connections.
- Monitor network traffic for anomalies.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52840.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52840 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-2026-52840
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-2026-52840 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52840 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 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 15, 2026
Action Type Old Value New Value Added Reference https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q Added SSVC {'id': 'CVE-2026-52840', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-15T13:53:03.540827Z'} -
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. In versions prior to 1.6.0, `Caldav::connect_to_server` at `application/controllers/Caldav.php:60` hands the request's `caldav_url` to a Guzzle `REPORT` call without scheme or host validation. A logged-in backend user (admin, provider, or secretary) reaches loopback, RFC1918, and link-local hosts on the deployment's network. The Guzzle exception path returns the upstream status code plus ~120 bytes of response body in the JSON `message` field (`Caldav.php:74-78`), so the SSRF is semi-blind. Version 1.6.0 contains a patch. Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-918 Added Reference https://github.com/alextselegidis/easyappointments/commit/6eb9336a91cfb276379506625e81f5bd9ed3a536 Added Reference https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q