CVE-2026-33704
Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint
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.
- Record
CVE-2026-33704- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L - Weakness
- CWE-434
- Updated
- 2026-11-02
EUVDEUVD-2026-21555
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.
- Record
EUVD-2026-21555- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-33704- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-434
- Updated
- 2026-11-02
OSV
Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint
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.
- Record
CVE-2026-33704- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L - Weakness
- CWE-434
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-33704 is a high vulnerability (CVSS 7.1) in Chamilo Lms, published April 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 36th percentile. No source names a fixed version.