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

> Unauthenticated attackers can inject scripts into survey answers, leading to arbitrary code execution and account takeover in Chamilo LMS.

- **Severity:** Medium 5.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 11 Sep 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-m3wr-p8wj-jmf6, GHSA-xf2f-2vj2-6hfr

## What is CVE-2026-82535?

CVE-2026-82535 is a medium-severity cross-site scripting vulnerability in chamilo-lms, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-82535?


## How do I fix CVE-2026-82535?

No fix has been published for CVE-2026-82535 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82535 being exploited?

There is no known exploitation of CVE-2026-82535 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82535 and fix it if it is affected.

What it is: CVE-2026-82535 is a medium-severity cross-site scripting vulnerability in chamilo-lms, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-82535 in the wild and no public exploit code.

Affected product: chamilo-lms. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82535/ (Markdown: https://insights.sbomify.com/CVE-2026-82535/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82535
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82535
- OSV: https://osv.dev/vulnerability/CVE-2026-82535

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-82535/
Summaries are generated and may contain mistakes; the official description above is the record.