# CVE-2026-57330: StylemixThemes MasterStudy LMS Cross-Site Scripting via Subscriber role

Source: https://junglewise.ai/threats/cve-2026-57330-stylemixthemes-masterstudy-lms-cross-site-scripting-via  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-29. Updated: 2026-06-29  
License: CC BY 4.0 with a link back

CVE-2026-57330 · Severity: medium · CVSS 6.5 · Published 2026-06-29

MasterStudy LMS is a popular WordPress plugin used to create and manage online courses and learning platforms. A security vulnerability in versions 3.7.27 and earlier allows users with basic 'Subscriber' accounts to inject malicious scripts into the website. If a site administrator or another user views the affected content, the attacker could potentially hijack sessions, redirect visitors to malicious websites, or deface the platform.

Technologies: [StylemixThemes MasterStudy LMS](https://junglewise.ai/threats/technologies/masterstudy-lms). Vendors: [StylemixThemes](https://junglewise.ai/threats/vendors/stylemixthemes).

## Quick answers

**Is CVE-2026-57330 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-57330 being exploited in the wild.

**How severe is CVE-2026-57330?** Medium severity, with a CVSS score of 6.5, published 29 June 2026.

**Which products and versions are affected?** StylemixThemes MasterStudy LMS <= 3.7.27.

**Is there a fix for CVE-2026-57330?** A patch was published on 2026-06-29: Fixed in version 3.7.28 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-57330 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-57330?** Check whether you run StylemixThemes MasterStudy LMS at an affected version. 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

A Cross-Site Scripting (XSS) vulnerability exists in the MasterStudy LMS plugin for WordPress due to improper neutralization of input during web page generation (CWE-79). The flaw allows authenticated attackers with Subscriber-level privileges to inject arbitrary web scripts. Successful exploitation requires a victim (such as an administrator) to interact with the malicious payload, leading to script execution in the context of the victim's browser. This is classified as a stored XSS vulnerability with a scope change (S:C). The issue is resolved in version 3.7.28.

## Affected products

- StylemixThemes MasterStudy LMS <= 3.7.27

## Timeline

- 2026-04-15: disclosed: Reported by researcher endy
- 2026-06-29: advisory
- 2026-06-29: patched: Fixed in version 3.7.28

## References

- [https://wordpress.org/plugins](https://wordpress.org/plugins)
- [https://patchstack.com/database/wordpress/plugin/masterstudy-lms-learning-management-system/vulnerability/wordpress-masterstudy-lms-plugin-3-7-27-cross-site-scripting-xss-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/masterstudy-lms-learning-management-system/vulnerability/wordpress-masterstudy-lms-plugin-3-7-27-cross-site-scripting-xss-vulnerability?_s_id=cve)

## Related threats

- [StylemixThemes MasterStudy LMS content injection via XSS](https://junglewise.ai/threats/cve-2026-119478-improper-neutralization-of-script-related-html-tags-in-a-web)
- [MasterStudy LMS PHP object injection in subscriber handling](https://junglewise.ai/threats/cve-2026-118090-subscriber-php-object-injection-in-masterstudy-lms-3-7-55)
- [MasterStudy LMS path traversal in file import](https://junglewise.ai/threats/cve-2026-80067-masterstudy-lms-plugin-for-wordpress-before-3-7-50-contains-a)
- [StylemixThemes MasterStudy LMS broken access control](https://junglewise.ai/threats/cve-2026-118092-missing-authorization-vulnerability-in-stylemixthemes)
- [MasterStudy LMS unauthenticated arbitrary file deletion](https://junglewise.ai/threats/cve-2026-78284-masterstudy-lms-unauthenticated-arbitrary-file-deletion)