# CVE-2026-19712: Masteriyo LMS < 2.3.3 - Instructor+ Stored XSS via Quiz Description

> Instructors can inject malicious scripts into quiz descriptions, leading to stored XSS attacks against site visitors and administrators.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A: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:** 16 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** GHSA-9qrh-j6xc-w4qf

## What is CVE-2026-19712?

CVE-2026-19712 is a medium-severity cross-site scripting vulnerability in Unknown Masteriyo LMS, published on 16 Aug 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

The Masteriyo LMS  WordPress plugin before 2.3.3 does not sanitise and escape a quiz field before outputting it back in a page, and grants its instructor role the ability to store unfiltered HTML, allowing such users to perform Stored Cross-Site Scripting attacks against any visitor of the affected page, including administrators.
This affects default single-site installations. Sites running multisite, or defining DISALLOW_UNFILTERED_HTML, are not affected as the capability is not granted there.

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

## Which versions are affected by CVE-2026-19712?


## How do I fix CVE-2026-19712?

No fix has been published for CVE-2026-19712 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-19712 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-19712 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-19712 and fix it if it is affected.

What it is: CVE-2026-19712 is a medium-severity cross-site scripting vulnerability in Unknown Masteriyo LMS, published on 16 Aug 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-19712 exists.

Affected product: Unknown Masteriyo 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-2026-19712/ (Markdown: https://insights.sbomify.com/CVE-2026-19712/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-19712
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-19712
- OSV: https://osv.dev/vulnerability/CVE-2026-19712

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-19712/
Summaries are generated and may contain mistakes; the official description above is the record.