CVE-2026-33704 Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint
Authenticated users can upload malicious files with .pht extensions to achieve remote code execution on Apache servers configured to process them as PHP.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33704?
CVE-2026-33704 is a high-severity vulnerability in Chamilo Chamilo Lms, published on 10 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Chamilo LMS is a learning management system. Prior to 1.11.38, any authenticated user (including students) can write arbitrary content to files on the server via the BigUpload endpoint. The key parameter controls the filename and the raw POST body becomes the file content. While .php extensions are filtered to .phps, the .pht extension passes through unmodified. On Apache configurations where .pht is handled as PHP, this leads to Remote Code Execution. This vulnerability is fixed in 1.11.38.
Weakness: CWE-434
Which versions are affected by CVE-2026-33704?
It affects 1 product.
Products include Chamilo Chamilo Lms.
How do I fix CVE-2026-33704?
No fix has been published for CVE-2026-33704 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-33704 being exploited?
There is no known exploitation of CVE-2026-33704 in the wild and no public exploit code.
Other vulnerabilities in Chamilo Chamilo Lms
Sources
Also known as GHSA-phfx-pwwg-945v.