CVE-2024-23176Network attack vector

Cross-site scripting via improperly escaped help message

Published Sep 14, 2026 · Updated Sep 14, 2026

Cross-site scripting in MediaWiki MassMessage before 1.40.2 allows remote attackers to execute script via a crafted language URL. Special:MassMessage renders the massmessage-form-page-help internationalization message without the help-message escaping required for safe output. A targeted user must open a Special:MassMessage?uselang=x-xss URL; injected script then runs in the wiki's browser origin.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in MediaWiki MassMessage before 1.40.2 allows remote attackers to execute script via a crafted language URL. Special:MassMessage renders the massmessage-form-page-help internationalization message without the help-message escaping required for safe output. A targeted user must open a Special:MassMessage?uselang=x-xss URL; injected script then runs in the wiki's browser origin.

The record

CVE
CVE-2024-23176
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
MediaWiki
Product
MassMessage
Classifications
T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 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=0 <1.40.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MediaWiki · MassMessageversion=0 <1.40.2

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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1203Exploitation for Client Execution

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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