CVE-2026-33715

HIGH

Chamilo LMS has Unauthenticated SSRF and Open Email Relay via install.ajax.php test_mailer action

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-33715. PoCs published by romain-deperne.

AI-analyzed exploit summary The repository contains a functional PoC for CVE-2026-33715, demonstrating an unauthenticated SSRF and open email relay vulnerability in Chamilo LMS via the install.ajax.php endpoint. The PoC includes a Python script that sends crafted requests to exploit the vulnerability.

Description

Chamilo LMS is an open-source learning management system. In version 2.0-RC.2, the file public/main/inc/ajax/install.ajax.php is accessible without authentication on fully installed instances because, unlike other AJAX endpoints, it does not include the global.inc.php file that performs authentication and installation-completed checks. Its test_mailer action accepts an arbitrary Symfony Mailer DSN string from POST data and uses it to connect to an attacker-specified SMTP server, enabling Server-Side Request Forgery (SSRF) into internal networks via the SMTP protocol. An unauthenticated attacker can also abuse this to weaponize the Chamilo server as an open email relay for phishing and spam campaigns, with emails appearing to originate from the server's IP address. Additionally, error responses from failed SMTP connections may disclose information about internal network topology and running services. This issue has been fixed in version 2.0.0-RC.3.

Exploits (1)

github WORKING POC
by romain-deperne · pythonpoc
https://github.com/romain-deperne/CVE-2026-33715

The repository contains a functional PoC for CVE-2026-33715, demonstrating an unauthenticated SSRF and open email relay vulnerability in Chamilo LMS via the install.ajax.php endpoint. The PoC includes a Python script that sends crafted requests to exploit the vulnerability.

Classification
Working Poc 100%
Attack Type
Ssrf
Complexity
Trivial
Reliability
Reliable
Target: Chamilo LMS 2.0 (commit 0195b29 and earlier)
No auth needed
Prerequisites: Access to the target Chamilo LMS instance
devstral-2 · analyzed Apr 30, 2026 Full analysis →

References (2)

Core 2

Scores

CVSS v3 7.2
EPSS 0.0021
EPSS Percentile 10.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-306 CWE-918
Status published
Products (2)
chamilo/chamilo-lms >= 2.0-RC.2, < 2.0-RC.3
chamilo/chamilo_lms 2.0.0 rc2
Published Apr 14, 2026
Tracked Since Apr 15, 2026