{"id":"CVE-2026-54355","revision":"44347c2ff3e84030af010d8346ae24f3","records":[{"revision":"44347c2ff3e84030af010d8346ae24f3","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-54355","aliases":[],"title":"MapServer: Reflected XSS in OpenLayers HTML Output via `HTTP_X_FORWARDED_HOST`","description":"MapServer is a system for developing web-based GIS applications. From 6.0 until 8.6.4, MapServer's OpenLayers HTML output for SERVICE=WMS&REQUEST=GetMap&FORMAT=application/openlayers reflects an attacker-controlled X-Forwarded-Host value received as HTTP_X_FORWARDED_HOST through msBuildOnlineResource(), processLine(), and the [mapserv_onlineresource] substitution in src/maputil.c and src/maptemplate.c without escaping it for a single-quoted JavaScript string. When the deployment trusts the forwarded header and does not configure a fixed ows_onlineresource or MS_ONLINERESOURCE value, embedded single quotes can escape the generated URL string. An unauthenticated attacker can craft a URL that executes arbitrary JavaScript in the MapServer site origin when opened by a victim, enabling access to sessions or tokens, same-origin data and requests, and actions as the victim. This issue is fixed in version 8.6.4.","state":0,"publishedAt":"2026-09-17T20:24:32.522+00:00","modifiedAt":"2026-09-24T20:45:56.071+00:00","affected":[{"ecosystem":"Vendor product","name":"MapServer","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"MapServer\",\n                    \"product\": \"MapServer\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 6.0, < 8.6.4\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":5.3,"severity":"MEDIUM"}],"references":["https://github.com/MapServer/MapServer/security/advisories/GHSA-xqj6-vjqr-33vv","https://github.com/MapServer/MapServer/pull/7517","https://github.com/MapServer/MapServer/pull/7518","https://github.com/MapServer/MapServer/commit/edc1033c7963fcffd160d85cf430f49aaf4a1374","https://github.com/MapServer/MapServer/commit/ff17ef190caaeaa9002ac3d1c7969ec5315c345e","https://github.com/MapServer/MapServer/releases/tag/rel-8-6-4","https://mapserver.org/development/changelog/changelog-8-6.html#changelog-8-6"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-54355","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-54355","identifiers":["CVE-2026-54355"]},"retained":false,"historicalAffected":[]}],"coverage":[]}