Vulnerability Report

CVE-2026-33715

Title: Unauthenticated Server-Side Request Forgery (SSRF) via Mailer DSN

Auth Bypass

Proof Of Concept

PoC Available for CVE-2026-33715

CWE Category CWE-306
Published Date Apr 14, 2026
Modified Date Apr 23, 2026
Exploit Status Available
Score 7.2 CVSS v3.1
Exploit Probability (EPSS)
0.21%

Vulnerability Summary

CVE-2026-33715: 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.

CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.2
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-33715 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/romain-deperne/CVE-2026-33715
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Affected Stack

No specific products linked.