How severe is CVE-2026-33704?

CVE-2026-33704 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability low.

Is CVE-2026-33704 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33704?

CVE-2026-33704 affects Chamilo Chamilo Lms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33704?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33704 have an EU (EUVD) identifier?

Yes. CVE-2026-33704 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21555.

When was CVE-2026-33704 published?

CVE-2026-33704 was published on 2026-04-10 and last updated on 2026-06-17.

CVE-2026-33704

CVE-2026-33704 is a high-severity vulnerability in Chamilo Chamilo Lms with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-434.

Key facts

Severity: High (CVSS 3.x base score 7.1)
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21555
Weakness: CWE-434
Affected product: Chamilo Chamilo Lms
Published: 2026-04-10
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-33704?: 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.
How severe is CVE-2026-33704?: CVE-2026-33704 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability low.
Is CVE-2026-33704 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33704?: CVE-2026-33704 affects Chamilo Chamilo Lms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33704?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33704 have an EU (EUVD) identifier?: Yes. CVE-2026-33704 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21555.
When was CVE-2026-33704 published?: CVE-2026-33704 was published on 2026-04-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:chamilo:chamilo_lms:*:*:*:*:*:*:*:*

More vulnerabilities in Chamilo Chamilo Lms

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Other CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities

CVE-2026-39770 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in Doctreat <= 1.7.0 versions.
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CVE-2026-102427 — Critical (CVSS 10.0): Joomla Extension - ordasoft.com - Unauthenticated Remote Code Execution in OrdaSoft Joomla CCK < 8.3.16 -…
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CVE-2026-84147 — Critical (CVSS 10.0): This vulnerability exists in the ERP system due to improper authentication controls and inadequate file type validation…
CVE-2026-81780 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in Hash Form <= 1.4.2 versions.

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