# CVE-2026-33715: Chamilo LMS has Unauthenticated SSRF and Open Email Relay via install.ajax.php test_mailer action

> Unauthenticated attackers can exploit an SSRF vulnerability in Chamilo LMS to access internal networks and use the server as an open email relay.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Apr 2026
- **Updated:** 15 Apr 2026
- **Also known as:** GHSA-mxc9-9335-45mc

## What is CVE-2026-33715?

CVE-2026-33715 is a high-severity server-side request forgery vulnerability in Chamilo Chamilo Lms, published on 14 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-918 (Server-Side Request Forgery), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-33715?

It affects 1 product.


Products: Chamilo Chamilo Lms.

## How do I fix CVE-2026-33715?

No fix has been published for CVE-2026-33715 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33715 being exploited?

There is no known exploitation of CVE-2026-33715 in the wild and no public exploit code.

Public exploit code:

- Unauthenticated SSRF and open email relay in Chamilo LMS — CVE-2026-33715 / CVSS 7.2 (github_poc): https://github.com/romain-deperne/CVE-2026-33715

## Other vulnerabilities in Chamilo Chamilo Lms

- [CVE-2025-50187](https://insights.sbomify.com/CVE-2025-50187/): Chamilo: Evaluation of untrusted user input leads to Remote Code Execution (critical 9.8)
- [CVE-2023-34944](https://insights.sbomify.com/CVE-2023-34944/): File upload in n/a (critical 9.8)
- [CVE-2022-27423](https://insights.sbomify.com/CVE-2022-27423/): SQL injection in n/a (critical 9.8)
- [CVE-2021-35414](https://insights.sbomify.com/CVE-2021-35414/): SQL injection in n/a (critical 9.8)
- [CVE-2019-13082](https://insights.sbomify.com/CVE-2019-13082/): File upload in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33715 and fix it if it is affected.

What it is: CVE-2026-33715 is a high-severity server-side request forgery vulnerability in Chamilo Chamilo Lms, published on 14 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33715 in the wild and no public exploit code.

Affected product: Chamilo Chamilo Lms. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33715/ (Markdown: https://insights.sbomify.com/CVE-2026-33715/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33715
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33715
- OSV: https://osv.dev/vulnerability/CVE-2026-33715

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33715/
Summaries are generated and may contain mistakes; the official description above is the record.