CVE-2026-34161mediumCWE-79

CVE-2026-34161: medium-severity vulnerability in chamilo-lms

Chamilo LMS: Stored XSS via Malicious File Upload in Social Post Attachments Leads to Arbitrary JavaScript Execution

Published · Updated

Follow this CVE+ Monitor chamilo-lms

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 5.1epss 0.2%
Chamilo LMS is an open-source learning management system. In versions prior to 2.0.0-RC.3, a Stored Cross-Site Scripting (XSS) vulnerability exists in the social post attachment upload functionality, where an authenticated user can upload a malicious HTML file containing JavaScript via the /api/social_post_attachments endpoint. The uploaded file is served back from the application at the generated contentUrl without sanitization, content type restrictions, or a Content-Disposition: attachment header, causing the JavaScript to execute in the browser within the application's origin. Because the payload is stored server-side and runs in the trusted origin, an attacker can perform session hijacking, account takeover, privilege escalation (if an admin views the link), and arbitrary actions on behalf of the victim. This issue has been fixed in version 2.0.0-RC.3.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
Affected products
chamilo · chamilo-lms
Related CVEs — chamilo-lms

In the same product, most dangerous first.

CVE-2025-50196HIGHChamilo: OS Command Injection in /plugin/vchamilo/views/editinstance.php via POST main_database parameterEPSS 3.1%CVE-2025-50194HIGHChamilo: OS Command Injection in /main/cron/lang/check_parse_lang.phpEPSS 3.0%CVE-2025-50197HIGHChamilo: OS Command Injection in /main/admin/sub_language_ajax.inc.php via POST new_language parameterEPSS 3.0%CVE-2025-50195HIGHChamilo: OS Command Injection in /plugin/vchamilo/views/manage.controller.phpEPSS 3.0%CVE-2025-50193HIGHChamilo: OS command Injection in /plugin/vchamilo/views/import.php with the POST to_main_database parameterEPSS 3.0%CVE-2026-35196HIGHChamilo LMS has OS Command Injection via export_all_certificates actionEPSS 1.8%