Vulnerability · Published Aug 18, 2026 · Assigned by GitHub_M
CVE-2026-52854mediawiki/maps: Stored XSS through the overlays parameter in the display_map parser function
High 8.6
In plain English
A high-severity cross-site scripting in Maps from ProfessionalWiki. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Maps is a MediaWiki extension that enables visualization of geographic data through dynamic embedded maps. Prior to version 12.1.3, the display_map parser function in the Leaflet service accepts attacker-controlled HTML in the overlays parameter, and resources/leaflet/jquery.leaflet.js uses the overlay name as a Leaflet layer-control label without escaping it. A wiki user with the edit permission can store malicious wikitext that causes script execution when another user previews or views the affected map. The script executes in the viewing user's browser session and can access data or perform actions available to that user. This issue is fixed in version 12.1.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | mediawiki/maps | 12.1.3 | GHSA-4h7g-5542-v3fc |
| Ubuntu:26.04:LTS | mediawiki | no fix listed | UBUNTU-CVE-2026-52854 |
| Ubuntu:26.10 | mediawiki | no fix listed | UBUNTU-CVE-2026-52854 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ProfessionalWiki | Maps | < 12.1.3 |
Weakness: CWE-79, CWE-80 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
References
- https://github.com/ProfessionalWiki/Maps/security/advisories/GHSA-4h7g-5542-v3fc x_refsource_CONFIRM
- https://github.com/ProfessionalWiki/Maps/pull/899 x_refsource_MISC
- https://github.com/ProfessionalWiki/Maps/commit/737a993fc2f40499e9bb22198fd1d56c25613806 x_refsource_MISC
- https://github.com/ProfessionalWiki/Maps/blob/12.1.3/RELEASE-NOTES.md x_refsource_MISC
- https://github.com/ProfessionalWiki/Maps/releases/tag/12.1.3 x_refsource_MISC