CVE-2026-82846Network attack vector

Stored XSS via unescaped course settings

Published Sep 5, 2026 · Updated Sep 6, 2026

Stored XSS in Themeisle Masteriyo LMS before 3.4.0 allows remote authenticated users to execute script through crafted course settings. The plugin stores course-author-controlled setting values and outputs them on a visitor-accessible course page without sanitization or contextual escaping. A course-author role is required to plant the payload; any visitor who views the affected course, including a logged-in administrator, runs it in that session.

CVSS severity6.8
Medium
EPSS probability0.24%
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 Themeisle Masteriyo LMS before 3.4.0 allows remote authenticated users to execute script through crafted course settings. The plugin stores course-author-controlled setting values and outputs them on a visitor-accessible course page without sanitization or contextual escaping. A course-author role is required to plant the payload; any visitor who views the affected course, including a logged-in administrator, runs it in that session.

The record

CVE
CVE-2026-82846
Published
Sep 5, 2026
Updated
Sep 6, 2026
Vendor
Query Solutions Ltd.
Product
Masteriyo LMS
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 6, 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=1.18.0 <3.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Query Solutions Ltd. · Masteriyo LMSversion=1.18.0 <3.4.0

Published CVSS scores

6.8CISA ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

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-79Cross-Site Scripting (XSS)
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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