CVE-2026-58519: Stored XSS through Cargo's map format

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-01 · updated 2026-10-25
Weakness: CWE-79

Description

Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in The Wikimedia Foundation Mediawiki - Cargo Extension allows Stored XSS. This issue affects Mediawiki - Cargo Extension: from * before 3.9.1.

Affected products

The Wikimedia Foundation Mediawiki - Cargo extension: before 3.9.1 — fixed in 3.9.1

How to fix

Upgrade to a fixed version: The Wikimedia Foundation Mediawiki - Cargo extension 3.9.1. Check the vendor advisory for mitigations.

References

https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Cargo/+/1277612
https://phabricator.wikimedia.org/T424140
https://phabricator.wikimedia.org/T424140

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