CVE-2026-58519Known exploitationNetwork attack vector

Stored XSS via unreserved map data container

Published Jul 1, 2026 · Updated Jul 1, 2026

Stored XSS in Wikimedia Foundation MediaWiki Cargo before 3.9.1 allows remote attackers to execute script through crafted map data. The map formatter stores user-controlled marker data in a span element's contents, allowing crafted wikitext or language conversion to create attacker-controlled map data that the browser interprets as executable content. A vulnerable wiki must render an attacker-supplied Cargo map; the stored script then runs in the browser context of affected pages and can act with a viewer's session privileges.

CVSS severity5.4
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Wikimedia Foundation MediaWiki Cargo before 3.9.1 allows remote attackers to execute script through crafted map data. The map formatter stores user-controlled marker data in a span element's contents, allowing crafted wikitext or language conversion to create attacker-controlled map data that the browser interprets as executable content. A vulnerable wiki must render an attacker-supplied Cargo map; the stored script then runs in the browser context of affected pages and can act with a viewer's session privileges.

The record

CVE
CVE-2026-58519
Published
Jul 1, 2026
Updated
Jul 1, 2026
Vendor
Wikimedia Foundation
Product
MediaWiki Cargo
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 1, 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=* <3.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wikimedia Foundation · MediaWiki Cargoversion=* <3.9.1

Published CVSS scores

6.9Wikimedia FoundationCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:A
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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Reported exploitation

Technologies

Your stack

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Your stack

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