dbcve.org
Chamilo LmsApplication · Chamilo

CVE-2026-33715

HIGH · 7.2 CVSS v3.1 Published 2026-04-14
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
81/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In Chamilo LMS 2.0-RC.2, the file install.ajax.php lacks authentication because it doesn't include global.inc.php. The test_mailer action accepts arbitrary Symfony Mailer DSN strings via POST, enabling attackers to specify any SMTP server. This creates SSRF to internal networks and weaponizes the server as an open email relay for phishing/spam, while error responses may leak internal network topology.

MitigationUpgrade to Chamilo LMS version 2.0.0-RC.3 or later, which includes the authentication check. Additionally, consider network segmentation to restrict outbound SMTP connections from the application server.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Chamilo LmsApplication
Affected:= 2.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate the vulnerable AJAX endpoint file
    Check if the file public/main/inc/ajax/install.ajax.php exists in your web root directory
    Affected if The file exists and is accessible via the web server
  2. Confirm Chamilo LMS version
    Check your installed Chamilo LMS version by looking at version files (such as version.php or a composer.json) or accessing the admin panel version information
    Affected if The installed version is exactly 2.0.0 (the affected version)
  3. Verify test_mailer action is reachable
    Attempt to access public/main/inc/ajax/install.ajax.php?action=test_mailer (or POST to this endpoint with action=test_mailer parameter) without providing any authentication credentials
    Affected if The endpoint responds without requiring authentication (returns any response rather than a 401/403 redirect)
  4. Check mailer DSN configuration exposure
    Examine your Chamilo configuration files (typically in config/ or app/config/) for mailer settings. Look for any DSN string configuration that could be overwritten by the test_mailer action
    Affected if The application allows arbitrary DSN strings to be processed through the test_mailer action, potentially overriding configured SMTP settings

You are affected if your Chamilo LMS installation is version 2.0.0 and the install.ajax.php file is accessible without authentication, allowing the test_mailer action to accept arbitrary SMTP server specifications.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Chamilo LMS version 2.0.0-RC.3 or later, which includes the authentication check. Additionally, consider network segmentation to restrict outbound SMTP connections from the application server.

Recommended fix High confidence

2.0.0-RC.3

  1. 1. Back up the current Chamilo LMS installation and database before making any changes.
  2. 2. Download Chamilo LMS version 2.0.0-RC.3 or later from the official Chamilo repository.
  3. 3. Replace the existing installation files with the new version, preserving configuration and user data.
  4. 4. Verify that the file public/main/inc/ajax/install.ajax.php now properly includes authentication checks via global.inc.php.
  5. 5. Test the application to ensure normal functionality is retained after the upgrade.
  6. 6. Confirm that the test_mailer endpoint now requires authentication and rejects unauthenticated requests.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Chamilo Lms Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-33715 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33715 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data