The Masteriyo LMS WordPress plugin suffers from a stored XSS vulnerability (CWE-79) due to improper neutralization of input in the question content parameter. This allows authenticated users with at least student-level privileges to inject arbitrary web scripts that execute in the context of other users viewing the injected content. The vulnerability affects all versions up to and including 1.13.3. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, required privileges at the low level, no user interaction, and impacts on confidentiality and integrity with no availability impact.

An attacker with authenticated access at student level or higher can inject malicious scripts into question content, which execute in the browsers of users who view the affected pages. This can lead to unauthorized actions or data disclosure within the context of the affected WordPress site. The impact is limited to confidentiality and integrity with no direct availability impact. There are no known active exploits reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict user privileges to trusted users only and consider disabling or limiting question content input from lower-privileged users to reduce risk. Monitor vendor channels for updates and apply patches promptly once released.