{"id":"CVE-2026-34161","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-34161","generatedAt":"2026-10-28T11:55:25.337Z","title":"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…","description":"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.","published":"2026-04-14T21:16:26.000Z","lastModified":"2026-07-24T22:10:00.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":5.1,"severity":"MEDIUM","vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-79"],"affected":["chamilo/chamilo lms"],"epss":{"score":0.00219,"percentile":0.12301,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/chamilo/chamilo-lms/commit/7c4965e48769d1d06413836429e386816a465c7f","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/chamilo/chamilo-lms/commit/da671d66a146887be3a16eabc5dcf0a92c55f7da","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/chamilo/chamilo-lms/releases/tag/v2.0.0-RC.3","tags":["Product","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-273p-jw9w-3g22","tags":["Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-34161","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}