GeoServer is an open source software server written in Java that allows users to share and edit geospatial data. A stored cross-site scripting (XSS) vulnerability exists in versions prior to 2.23.3 and 2.24.1 that enables an authenticated administrator with workspace-level privileges to store a JavaScript payload in the GeoServer catalog that will execute in the context of another user's browser when viewed in the WMS GetMap OpenLayers Output Format. Access to the WMS OpenLayers Format is available to all users by default although data and service security may limit users' ability to trigger the XSS. Versions 2.23.3 and 2.24.1 contain a patch for this issue.
https://osgeo-org.atlassian.net/browse/GEOS-11153
https://github.com/geoserver/geoserver/security/advisories/GHSA-fcpm-hchj-mh72
https://github.com/geoserver/geoserver/pull/7174
https://github.com/geoserver/geoserver/commit/a26c32a469ee4c599236380452ffb4260361bd6f
https://github.com/geoserver/geoserver/commit/4557a832eed19ec18b9753cb97e8aa85269741d2