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TI-2026-26083 Aliases CVE-2026-33704

Chamilo LMS Affected by Authenticated Arbitrary File Write via BigUpload endpoint

Priority LOW 38CWE-434Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-434.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00436 38th percentileScored 2026-11-07
Fix Fixed chamilo-lms (chamilo): 1.11.38

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
chamilochamilo-lmsbefore 1.11.381.11.38Patch availableCNA
  • chamilo-lms Vendorchamilo Affected before 1.11.38 Fixed in 1.11.38 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:chamilo:chamilo_lms:*:*:*:*:*:*:*:*before 1.11.38Vulnerablechamilo
  • cpe:2.3:a:chamilo:chamilo_lms:*:*:*:*:*:*:*:* Versions before 1.11.38 Vulnerable ·chamilo

Remediation

  • Fix · CNA chamilo-lms (chamilo) Fixed in 1.11.38

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33704
  2. 2026-10-25 EPSS moved to the below the 50th percentile

References

Patch 1

Advisory 1

  • TI-2025-32070 Chamilo: Evaluation of untrusted user input leads to Remote Code Execution CVSS 3.1CRITICAL 9.8
  • TI-2025-32081 Deserialization of untrusted data in chamilo-lms CVSS 4.0HIGH 8.8
  • TI-2024-32140 Chamilo: Post-Auth Remote Code Execution CVSS 4.0HIGH 8.7
  • TI-2023-03907 Chamilo LMS Unauthenticated Big Upload File Remote Code Execution CVSS 3.1HIGH 8.1
  • TI-2025-32595 Chamilo: Stored XSS Vulnerability via CSV User Import CVSS 3.1HIGH 8.8
  • TI-2024-20321 Chamilo LMS 1.11.26 is vulnerable to Incorrect Access Control via main/auth/profile. CVSS 3.1HIGH 8.8
See all 121 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences