CVE-2025-53494Public exploitNetwork attack vector

Stored XSS via unescaped preview system message

Published Jul 2, 2025 · Updated Jul 10, 2025

Stored XSS in Wikimedia Foundation MediaWiki TwoColConflict before 1.39.13, 1.42.7, and 1.43.2 allows attackers to run script. The SplitTwoColConflict preview handler appends the stored MediaWiki:Preview system message as raw HTML without escaping it. Exploitation requires control of that system message and a user with live preview enabled to open an edit conflict, select a version, and request a preview; injected JavaScript then executes in that user's browser.

CVSS severity6.5
Medium
EPSS probability0.23%
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 Wikimedia Foundation MediaWiki TwoColConflict before 1.39.13, 1.42.7, and 1.43.2 allows attackers to run script. The SplitTwoColConflict preview handler appends the stored MediaWiki:Preview system message as raw HTML without escaping it. Exploitation requires control of that system message and a user with live preview enabled to open an edit conflict, select a version, and request a preview; injected JavaScript then executes in that user's browser.

The record

CVE
CVE-2025-53494
Published
Jul 2, 2025
Updated
Jul 10, 2025
Vendor
Wikimedia Foundation
Product
MediaWiki TwoColConflict Extension
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 10, 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?

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

  1. Affected versionversion=1.39.x <1.39.13
  2. Affected versionversion=1.42.x <1.42.7
  3. Affected versionversion=1.43.x <1.43.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Wikimedia Foundation · MediaWiki TwoColConflict Extensionversion=1.39.x <1.39.13; version=1.42.x <1.42.7; version=1.43.x <1.43.2

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-592Stored XSS
T1059.007Command and Scripting Interpreter: JavaScript

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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