Vulnerability · Published Apr 14, 2026 · Assigned by GitHub_M
CVE-2026-33715Chamilo LMS has Unauthenticated SSRF and Open Email Relay via install.ajax.php test_mailer action
High 7.2
In plain English
A high-severity missing authentication in chamilo-lms from chamilo. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| chamilo | chamilo-lms | >= 2.0-RC.2, < 2.0-RC.3 |
Weakness: CWE-306, CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
References
- https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-mxc9-9335-45mc x_refsource_CONFIRM
- https://github.com/chamilo/chamilo-lms/releases/tag/v2.0.0-RC.3 x_refsource_MISC