CVE-2025-51489Public exploitNetwork attack vector

Stored XSS via unrestricted SVG thumbnail upload

Published Aug 19, 2025 · Updated Aug 20, 2025

Stored XSS in MoonShine before 3.12.5 allows remote authenticated users to execute JavaScript through a malicious article thumbnail. The article Files → Thumbnail field accepts an SVG containing script, and the saved file executes that script when its link is opened. Article-creation access and a victim opening the uploaded file are required; the script runs within the victim's application origin.

CVSS severity5.4
Medium
EPSS probability0.34%
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 MoonShine before 3.12.5 allows remote authenticated users to execute JavaScript through a malicious article thumbnail. The article Files → Thumbnail field accepts an SVG containing script, and the saved file executes that script when its link is opened. Article-creation access and a victim opening the uploaded file are required; the script runs within the victim's application origin.

The record

CVE
CVE-2025-51489
Published
Aug 19, 2025
Updated
Aug 20, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, CWE-434, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
4.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-434Unrestricted Upload of File with Dangerous Type
T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

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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