CVE-2026-33704Network attack vector

Authenticated code execution via unfiltered .pht upload

Published Apr 10, 2026 · Updated Apr 10, 2026

Arbitrary file write in Chamilo LMS before 1.11.38 allows remote authenticated users to write server files through BigUpload. BigUpload's uploadFile() appends the raw POST body to an app/cache filename derived from the key parameter after a filter that misses .pht. Student-level access is enough; on Apache systems configured to execute .pht as PHP, a file in the web-accessible cache grants remote code execution.

CVSS severity7.1
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file write in Chamilo LMS before 1.11.38 allows remote authenticated users to write server files through BigUpload. BigUpload's uploadFile() appends the raw POST body to an app/cache filename derived from the key parameter after a filter that misses .pht. Student-level access is enough; on Apache systems configured to execute .pht as PHP, a file in the web-accessible cache grants remote code execution.

The record

CVE
CVE-2026-33704
Published
Apr 10, 2026
Updated
Apr 10, 2026
Vendor
Chamilo
Product
Chamilo LMS
Classifications
CWE-434, T1190, T1505.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.11.38

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Chamilo · Chamilo LMSversion=< 1.11.38

Published CVSS scores

7.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1190Exploit Public-Facing Application
T1505.003Server Software Component: Web Shell

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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