# CVE-2026-58519: Wikimedia MediaWiki Cargo Extension stored XSS in map format

Source: https://junglewise.ai/threats/cve-2026-58519-wikimedia-mediawiki-cargo-extension-stored-xss-in-map-format  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-01. Updated: 2026-07-01  
License: CC BY 4.0 with a link back

CVE-2026-58519 · Severity: info · CVSS 6.9 · Published 2026-07-01

The Cargo extension for MediaWiki, which allows users to store and query data within wiki pages, contains a vulnerability that allows for stored cross-site scripting (XSS). An attacker can inject malicious scripts into map data that will execute in the browser of any user viewing the affected page. This could lead to unauthorized actions being performed on behalf of users, including administrative account takeover or the theft of sensitive session information.

Technologies: [Wikimedia Foundation Cargo Extension](https://junglewise.ai/threats/technologies/cargo-extension). Vendors: [Wikimedia Foundation](https://junglewise.ai/threats/vendors/wikimedia-foundation).

## Quick answers

**Is CVE-2026-58519 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-58519 being exploited in the wild.

**How severe is CVE-2026-58519?** Informational severity, with a CVSS score of 6.9, published 1 July 2026.

**Which products and versions are affected?** Wikimedia Foundation Cargo Extension before 3.9.1.

**Is there a fix for CVE-2026-58519?** A patch was published on 2026-04-27: Fix merged into master branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-58519 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-58519?** Check whether you run Wikimedia Foundation Cargo Extension at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stored cross-site scripting (XSS) vulnerability exists in the Cargo extension for MediaWiki due to improper neutralization of input in the 'map' format. Cargo previously stored map data as JSON within the inner content of a <span> element, which could be spoofed or manipulated via wikitext or the language converter. An attacker can craft malicious wikitext containing a fake .cargoMapData element with an XSS payload in the 'title' or 'name' fields. When a user clicks on a map marker, the payload executes in the context of their session. The fix, introduced in version 3.9.1, moves map data to a reserved 'data-mw-cargo-map-data' attribute and ignores elements lacking this attribute.

## Affected products

- The Wikimedia Foundation MediaWiki - Cargo Extension before 3.9.1

## Timeline

- 2026-04-22: disclosed: Vulnerability reported to Wikimedia Phabricator
- 2026-04-27: patched: Fix merged into master branch
- 2026-07-01: advisory: CVE published and NVD record created

## References

- [https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Cargo/+/1277612](https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Cargo/+/1277612)
- [https://phabricator.wikimedia.org/T424140](https://phabricator.wikimedia.org/T424140)

## Related threats

- [Wikimedia MediaWiki Cargo Extension stored XSS in list fields](https://junglewise.ai/threats/cve-2026-39841-wikimedia-mediawiki-cargo-extension-stored-xss-in-list-fields)
- [Wikimedia MediaWiki Cargo Extension stored XSS in map format](https://junglewise.ai/threats/cve-2026-39839-wikimedia-mediawiki-cargo-extension-stored-xss-in-map-format)
- [Wikimedia MediaWiki Cargo Extension stored XSS in dynamic table format](https://junglewise.ai/threats/cve-2026-39837-wikimedia-mediawiki-cargo-extension-stored-xss-in-dynamic-table)