---
id: CVE-2026-82535
title: >-
  Chamilo LMS before 1.11.42 and 3.0.0 contains a stored cross-site scripting
  vulnerability that allows unauthenticated attackers to inject malicious script
  payloads into survey answers by computing deterministic invitation codes and
  bypas…
summary: >-
  Chamilo LMS before 1.11.42 and 3.0.0 contains a stored cross-site scripting
  vulnerability that allows unauthenticated attackers to inject malicious script
  payloads into survey answers by computing deterministic invitation codes and
  bypas…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: chamilo
product: chamilo-lms
affected:
  - chamilo-lms >= 1.11.0 <= 1.11.40
  - chamilo-lms >= 2.0.0 <= 2.0.3
published: '2026-09-11'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:43:32.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-82535'
references:
  - url: >-
      https://github.com/chamilo/chamilo-lms/commit/be45f2f2a29319afbbf9ce27d094698911799d10
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/chamilo/chamilo-lms/commit/bea9cbcfc6ca58f387c6c25bef2f15dc5df9d147
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/chamilo/chamilo-lms/commit/c9d2614d798571b94cef1cb61e605a2fc89f0386
    label: disclosure@vulncheck.com
  - url: 'https://github.com/chamilo/chamilo-lms/releases/tag/v3.0.0'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-m3wr-p8wj-jmf6
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/chamilo-lms-stored-xss-via-survey-answer-submission-in-reporting-php
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.00474
epssPercentile: 0.38379
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-11T19:21:14.253000Z'
ingestedAt: '2026-09-14T00:35:28.533Z'
---

## Overview

Chamilo LMS before 1.11.42 and 3.0.0 contains a stored cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious script payloads into survey answers by computing deterministic invitation codes and bypassing authorization checks in the survey submission endpoint. Attackers can submit crafted answers containing unescaped HTML rendered in reporting views to execute arbitrary scripts in the browser sessions of teachers or administrators, enabling persistent backdoor account creation by exploiting the victim's authenticated session.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.