CVE-2026-0559Network attack vector

Stored XSS via unescaped courses-grid shortcode attributes

Published Feb 14, 2026 · Updated Feb 14, 2026

Stored XSS in StylemixThemes MasterStudy LMS 3.7.11 and earlier allows remote authenticated users to inject scripts through a shortcode. The stm_lms_courses_grid_display shortcode handler insufficiently sanitizes user-supplied attributes and renders them without adequate output escaping. Contributor-level access is required; injected scripts execute in the browsers of users who view the affected page, enabling actions in those users' sessions.

CVSS severity6.4
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in StylemixThemes MasterStudy LMS 3.7.11 and earlier allows remote authenticated users to inject scripts through a shortcode. The stm_lms_courses_grid_display shortcode handler insufficiently sanitizes user-supplied attributes and renders them without adequate output escaping. Contributor-level access is required; injected scripts execute in the browsers of users who view the affected page, enabling actions in those users' sessions.

The record

CVE
CVE-2026-0559
Published
Feb 14, 2026
Updated
Feb 14, 2026
Vendor
StylemixThemes
Product
MasterStudy LMS
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=* <=3.7.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

StylemixThemes · MasterStudy LMSversion=* <=3.7.11

Published CVSS scores

6.4WordfenceCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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