CVE-2026-82851

Masteriyo LMS – LMS Course Builder, Quizzes & Certificates 1.14.0 - 3.4.0 - Authenticated (Custom Role+) Insecure Direct Object Reference

2026-09-12 00:00

Strategic Overview

Status: Patched in 3.4.1
Affected Plugin: Masteriyo LMS – LMS Course Builder, Quizzes & Certificates
Affected Version: 1.14.0 – 3.4.0
CVSS: 4.3Medium
Weakness type: CWE-639 · Authorization Bypass Through User-Controlled Key
CVE: CVE-2026-82851

View all Masteriyo LMS – LMS Course Builder, Quizzes & Certificates vulnerabilities

At a glance

CVE-2026-82851 is a medium-severity Authorization Bypass Through User-Controlled Key vulnerability in the Masteriyo LMS WordPress plugin, affecting versions 1.14.0 – 3.4.0. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Custom Role level or above. The issue is fixed in version 3.4.1; sites on affected versions should update now. Disclosed September 2026, reported by Karthik Ramakrishnan.

Vulnerability Overview

The Masteriyo LMS – LMS Course Builder, Quizzes & Certificates plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions 1.14.0 through 3.4.0. This is due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with custom role-level access and above, to perform an unauthorized action.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.

CWE-639: Authorization Bypass Through User-Controlled Key

Reaching this weakness in Masteriyo LMS 1.14.0 – 3.4.0 takes an account at Custom Role level or above. Authorization bypass through a user-controlled key, often called insecure direct object reference, means the application looks up a record by an identifier from the request without checking that the caller owns it.

Changing a number in the request is enough to read or modify other users' records, which on commerce and membership sites means customer data. For Masteriyo LMS the fix is 3.4.1: builds 1.14.0 – 3.4.0 are affected, anything from 3.4.1 onward is not.

Remediation

Update to version 3.4.1, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Masteriyo LMS 3.4.1 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-82851 https://www.wordfence.com/threat-intel/vulnerabilities/id/9df0d33d-6b07-4e5c-bfa0-6f618a969f23 https://nvd.nist.gov/vuln/detail/CVE-2026-82851

Related records

Same weakness class

Other vulnerabilities in Masteriyo LMS – LMS Course Builder, Quizzes & Certificates

CVSS Vector

4.3

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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