CVE-2026-33704CWE-434

Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint

High · published April 10, 2026

CVSS v3.1
7.1
EPSS
1%
Percentile
54.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.00756 · 54.7th percentile
Weakness
CWE-434 · Unrestricted Upload of File with Dangerous Type
Published
2026-04-10T18:30Z
EPSS history
Timeline
  • 10 APR 18:30Z
    Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint
    cvelistv5