mediawiki/maps has stored XSS through the overlays parameter in the display_map parser function (CVE-2026-52854)
### Summary Stored XSS through wikitext can be performed by inserting malicious HTML into the `overlays` parameter of the `display_map` parser function when using the leaflet service. ### Details The maps extension doesn't escape overlay names before passing them to leaflet. Leaflet then inserts them as HTML: https://github.com/ProfessionalWiki/Maps/blob/ca5139fabd75f3c34f47ea3fd161306506b053bc/resources/lib/leaflet/leaflet.js#L5243 ### PoC Preview the following wikitext, using the default configuration options of the extension: ``` {{#display_map:0,0|service=leaflet|overlays=OpenTopoMap.<img src=x onerror="alert(1);">}} ``` ### Impact Stored XSS can be performed by any user with the `edit` permission.
AI Analysis
Technical Summary
The mediawiki/maps extension prior to version 12.1.3 contains a stored XSS vulnerability (CVE-2026-52854) in the display_map parser function's overlays parameter when used with the leaflet service. Overlay names are not escaped before being passed to leaflet.js, which inserts them directly as HTML, enabling stored XSS attacks. An attacker with edit permissions can inject malicious HTML/JavaScript via the overlays parameter in wikitext, which will execute in the context of users viewing the map. This vulnerability is tracked as CWE-79 and CWE-80 and has a high severity rating.
Potential Impact
Successful exploitation allows an attacker with edit permissions to perform stored XSS attacks, potentially leading to arbitrary script execution in the browsers of users viewing the affected maps. This can result in session hijacking, defacement, or other malicious actions. The vulnerability affects confidentiality, integrity, and availability as indicated by the CVSS vector (C:H/I:L/A:L).
Mitigation Recommendations
A fix is available in mediawiki/maps version 12.1.3 and later. Users should upgrade to version 12.1.3 or newer to remediate this vulnerability. Until upgraded, restrict edit permissions to trusted users only to reduce risk. Patch status is confirmed by the affectedVersions data indicating versions prior to 12.1.3 are vulnerable.
mediawiki/maps has stored XSS through the overlays parameter in the display_map parser function (CVE-2026-52854)
Description
### Summary Stored XSS through wikitext can be performed by inserting malicious HTML into the `overlays` parameter of the `display_map` parser function when using the leaflet service. ### Details The maps extension doesn't escape overlay names before passing them to leaflet. Leaflet then inserts them as HTML: https://github.com/ProfessionalWiki/Maps/blob/ca5139fabd75f3c34f47ea3fd161306506b053bc/resources/lib/leaflet/leaflet.js#L5243 ### PoC Preview the following wikitext, using the default configuration options of the extension: ``` {{#display_map:0,0|service=leaflet|overlays=OpenTopoMap.<img src=x onerror="alert(1);">}} ``` ### Impact Stored XSS can be performed by any user with the `edit` permission.
CVSS v3.1
Score 8.6high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The mediawiki/maps extension prior to version 12.1.3 contains a stored XSS vulnerability (CVE-2026-52854) in the display_map parser function's overlays parameter when used with the leaflet service. Overlay names are not escaped before being passed to leaflet.js, which inserts them directly as HTML, enabling stored XSS attacks. An attacker with edit permissions can inject malicious HTML/JavaScript via the overlays parameter in wikitext, which will execute in the context of users viewing the map. This vulnerability is tracked as CWE-79 and CWE-80 and has a high severity rating.
Potential Impact
Successful exploitation allows an attacker with edit permissions to perform stored XSS attacks, potentially leading to arbitrary script execution in the browsers of users viewing the affected maps. This can result in session hijacking, defacement, or other malicious actions. The vulnerability affects confidentiality, integrity, and availability as indicated by the CVSS vector (C:H/I:L/A:L).
Mitigation Recommendations
A fix is available in mediawiki/maps version 12.1.3 and later. Users should upgrade to version 12.1.3 or newer to remediate this vulnerability. Until upgraded, restrict edit permissions to trusted users only to reduce risk. Patch status is confirmed by the affectedVersions data indicating versions prior to 12.1.3 are vulnerable.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-4h7g-5542-v3fc
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-52854"]
- Ecosystems
- ["Packagist"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a46ecc327e9c7971943d5cc
Added to database: 07/02/2026, 22:57:07 UTC
Last enriched: 07/02/2026, 23:16:58 UTC
Last updated: 07/31/2026, 12:27:30 UTC
Views: 62
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