Is CVE-2026-82846 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-82846 being exploited in the wild.

How severe is CVE-2026-82846?

Medium severity, with a CVSS score of 6.8, published 5 September 2026.

Which products and versions are affected?

Masteriyo LMS 1.18.0 through 3.3.3.

Is there a fix for CVE-2026-82846?

A patch was published on 2026-09-05: Fixed in version 3.4.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-82846 attacked?

It is attacked over the network.

Am I affected by CVE-2026-82846?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-82846: Masteriyo LMS stored cross-site scripting in course custom fields

CVE-2026-82846 · Severity: medium · CVSS 6.8 · Published 2026-09-05

Masteriyo LMS is a WordPress plugin for building and managing online learning courses. The plugin fails to properly sanitize course custom field data before displaying it to visitors, allowing instructors to inject malicious scripts that execute in the browsers of anyone viewing the course—including administrators with full site access. An attacker with instructor privileges can exploit this to steal credentials, modify course content, or compromise the entire WordPress site.

Quick answers

Is CVE-2026-82846 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-82846 being exploited in the wild.
How severe is CVE-2026-82846?: Medium severity, with a CVSS score of 6.8, published 5 September 2026.
Which products and versions are affected?: Masteriyo LMS 1.18.0 through 3.3.3.
Is there a fix for CVE-2026-82846?: A patch was published on 2026-09-05: Fixed in version 3.4.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-82846 attacked?: It is attacked over the network.
Am I affected by CVE-2026-82846?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

This is a stored cross-site scripting (XSS) vulnerability in the Masteriyo LMS WordPress plugin (versions before 3.4.0). The vulnerability occurs because course custom field labels and values are not properly sanitized or escaped before being output in a JSON block on publicly-viewable course pages. An authenticated user with the course-author (instructor) role can inject arbitrary HTML and JavaScript via the REST API endpoint `/masteriyo/v1/courses` by crafting malicious payloads in custom field values or keys. The injected payload breaks out of the JSON context and executes as HTML in the page, running in the security context of any visitor, including administrators. The attack requires valid instructor credentials and WordPress REST nonce, but does not require administrator approval of the injected content. Patch is available in version 3.4.0 and later.

Affected products

Masteriyo LMS 1.18.0 through 3.3.3

Timeline

2026-09-03: disclosed
2026-09-05: patched: Fixed in version 3.4.0

References

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

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