CVE-2026-4817

MasterStudy LMS <= 3.7.25 - Authenticated (Subscriber+) Time-based Blind SQL Injection via 'order' and 'orderby' Parameters

2026-04-16 12:48
Naoya Takahashi (nakko)

Strategic Overview

Status
Patched in 3.7.26
Affected Version
<= 3.7.25
CVSS
6.5Medium
Weakness type
CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CVE
CVE-2026-4817
View all MasterStudy LMS WordPress Plugin – for Online Courses and Education vulnerabilities

At a glance

CVE-2026-4817 is a medium-severity Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in the MasterStudy LMS WordPress Plugin WordPress plugin, affecting versions <= 3.7.25. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 3.7.26; sites on affected versions should update now. Disclosed April 2026, reported by Naoya Takahashi (nakko).

Vulnerability Overview

The MasterStudy LMS WordPress Plugin for Online Courses and Education plugin for WordPress is vulnerable to Time-based Blind SQL Injection via the 'order' and 'orderby' parameters in the /lms/stm-lms/order/items REST API endpoint in versions up to and including 3.7.25. This is due to insufficient input sanitization combined with a design flaw in the custom Query builder class that allows unquoted SQL injection in ORDER BY clauses. When the Query builder detects parentheses in the sort_by parameter, it treats the value as a SQL function and directly concatenates it into the ORDER BY clause without any quoting. While esc_sql() is applied to escape quotes and backslashes, this cannot prevent ORDER BY injection when the values themselves are not wrapped in quotes in the resulting SQL statement. This makes it possible for authenticated attackers, with subscriber-level access and above, to append arbitrary SQL queries via the ORDER BY clause to extract sensitive information from the database including user credentials, session tokens, and other confidential data through time-based blind SQL injection techniques.

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. A successful exploit has high impact on confidentiality.

CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

MasterStudy LMS WordPress Plugin <= 3.7.25 carries this weakness at order, and reaching it takes an account at Subscriber level or above. SQL injection happens when request data is concatenated into a query instead of being bound as a parameter, letting an attacker change the structure of the statement rather than just its values.

A working injection can read any table the database user can see, which on a WordPress install means user records, password hashes and session or API secrets stored in options. For MasterStudy LMS WordPress Plugin the fix is 3.7.26: builds <= 3.7.25 are affected, anything from 3.7.26 onward is not.

Remediation

Update to version 3.7.26, or a newer patched version

How does WordSec protect against this?

An attacker needs Subscriber access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: MasterStudy LMS WordPress Plugin 3.7.26 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

Related records

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