CVE-2026-59513Network attack vector

Stored XSS via unsanitized course review content

Published Jul 23, 2026 · Updated Jul 23, 2026

Stored XSS in course reviews in Masteriyo LMS 2.3.0 and earlier allows remote authenticated users to execute scripts in visitors' browsers. The course-review submission path stores subscriber-controlled review content without adequate validation before that content is rendered as HTML. Subscriber access is sufficient to plant the payload, but execution requires a more privileged user to view the affected review.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
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 course reviews in Masteriyo LMS 2.3.0 and earlier allows remote authenticated users to execute scripts in visitors' browsers. The course-review submission path stores subscriber-controlled review content without adequate validation before that content is rendered as HTML. Subscriber access is sufficient to plant the payload, but execution requires a more privileged user to view the affected review.

The record

CVE
CVE-2026-59513
Published
Jul 23, 2026
Updated
Jul 23, 2026
Vendor
ThemeGrill
Product
Masteriyo LMS
Classifications
T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 23, 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=n/a <=2.3.0 changes=[{"at":"2.3.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ThemeGrill · Masteriyo LMSversion=n/a <=2.3.0 changes=[{"at":"2.3.1","status":"unaffected"}]

Published CVSS scores

No CVSS assessment is available in this record.

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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