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Fencer Intel
high 7.1

CVE-2026-33704 json

Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint

published 6mo ago modified 14d ago also EUVD-2026-21555

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Patch / fix

  • chamilo chamilo 1.11.38
  • chamilo chamilo_lms 1.11.38

Is CVE-2026-33704 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • chamilo chamilo-lms

Classification

Weakness
  • CWE-434 Unrestricted Upload of File with Dangerous Type

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.