# CVE-2026-33698: Chamilo LMS unauthenticated RCE in main/install directory

Source: https://junglewise.ai/threats/cve-2026-33698-chamilo-lms-unauthenticated-rce-in-main-install-directory  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-10. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2026-33698 · Severity: critical · CVSS 9.8 · Published 2026-04-10

Chamilo LMS is a popular open-source learning management system used by educational institutions and businesses to deliver online courses. A critical vulnerability allows unauthenticated attackers to bypass security restrictions and execute malicious code on the server. This could lead to a complete system takeover, unauthorized access to student and teacher data, or the modification of course content.

Technologies: [Chamilo Lms](https://junglewise.ai/threats/technologies/chamilo-lms). Vendors: [Chamilo](https://junglewise.ai/threats/vendors/chamilo).

## Quick answers

**Is CVE-2026-33698 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33698 being exploited in the wild.

**How severe is CVE-2026-33698?** Critical severity, with a CVSS score of 9.8, published 10 April 2026.

**Which products and versions are affected?** Chamilo Chamilo LMS < 1.11.38.

**Is there a fix for CVE-2026-33698?** A patch was published on 2026-03-23: Fix committed to repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-33698 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-33698?** Check whether you run Chamilo Lms. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A remote code execution (RCE) vulnerability exists in Chamilo LMS due to improper access controls and input handling in the 'main/install/' directory. An unauthenticated attacker can chain multiple flaws to bypass restrictions that normally block PHP execution in the installation folder. By sending specially crafted requests, the attacker can modify existing configuration files (such as app/config/configuration.php) or create new malicious files on the server. This vulnerability specifically affects installations where the 'main/install/' directory was not removed after the initial setup and remains web-accessible. The fix involves stricter validation of installer variables and removing the vulnerable scripts.

## Affected products

- Chamilo Chamilo LMS < 1.11.38

## Timeline

- 2026-03-23: patched: Fix committed to repository
- 2026-04-10: disclosed: Initial advisory published
- 2026-04-10: advisory: GitHub Security Advisory published
- 2026-04-16: other: NIST analysis completed

## References

- [https://github.com/chamilo/chamilo-lms/commit/d3355d7873c7e5b907c5fa84cbd5d9b62ed33e51](https://github.com/chamilo/chamilo-lms/commit/d3355d7873c7e5b907c5fa84cbd5d9b62ed33e51)
- [https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-557g-2w66-gpmf](https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-557g-2w66-gpmf)

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