CVE-2026-118090: MasterStudy LMS WordPress Plugin PHP object injection vulnerability

high 8.8 published 2026-10-30

Affected versions: 3.7.55 and older
Fixed in: 3.7.56
Latest version: 3.7.58
Severity: High · CVSS 8.8
Active installs: 10,000+
Type: PHP object injection

What an attacker needs

Access: A low-level account on the site, such as a subscriber or customer (per the CVSS score).

CVSS vector (score by Patchstack): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

What to do now

Update MasterStudy LMS WordPress Plugin to 3.7.56 or newer (the latest is 3.7.58): Dashboard → Updates, or Plugins → “update now”.
If you cannot update right away, deactivate it until you can.
Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
Not sure which version you run? Check your version against every known MasterStudy LMS WordPress Plugin issue. With WP-CLI: wp plugin get masterstudy-lms-learning-management-system --field=version.
If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.

The advisory

Subscriber PHP Object Injection in MasterStudy LMS <= 3.7.55 versions.

Description from the CVE record, published by Patchstack (the CVE Numbering Authority), via the NVD entry for CVE-2026-118090.

References

NVD CVE-2026-118090 nvd.nist.gov
Patchstack advisory patchstack.com

Ran an affected version? Check your site for signs of a hack

The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.

Where this data comes from

CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Versions and install counts: wordpress.org/plugins/masterstudy-lms-learning-management-system (Plugins API), fetched 2026-11-04.
The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.