{"id":"CVE-2026-54355","aliases":["DEBIAN-CVE-2026-54355","EUVD-2026-82433","GHSA-xqj6-vjqr-33vv","UBUNTU-CVE-2026-54355"],"status":"published","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\u0026REQUEST=GetMap\u0026FORMAT=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.","severity":{"version":"4.0","score":5.3,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.005,"percentile":0.43127,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2026-09-17T20:24:32Z","modified":"2026-10-28T10:52:08Z","fixes":[{"ecosystem":"Debian:14","package":"mapserver","fixed_in":["8.6.4-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.0.0-3","8.0.0-3+deb12u1","8.0.1-1","8.0.1-1~exp1","8.0.1-2","8.0.1-2.1~exp1","8.0.1-2~bpo12+1","8.0.1-3","8.0.1-3~exp1","8.0.1-4","8.0.1-5","8.0.2-1","8.0.2-1~bpo12+1","8.2.0-1","8.2.0-1~bpo12+1","8.2.0~beta1-1~exp1","8.2.0~beta2-1~exp1","8.2.0~beta3-1~exp1","8.2.0~rc1-1~exp1","8.2.0~rc2-1~exp1","8.2.0~rc3-1~exp1","8.2.1-1","8.2.1-1~bpo12+1","8.2.2-1","8.2.2-1~bpo12+1","8.4.0-1","8.4.0-1~bpo12+1","8.4.0-2","8.4.0-3","8.4.0-4","8.4.0~beta1-1~exp1","8.4.0~beta2-1~exp1","8.4.0~rc1-1~exp1","8.4.1-1","8.4.1-1~bpo13+1","8.4.1-2","8.6.0-1","8.6.0-1~bpo13+1","8.6.0~beta1-1~exp1","8.6.0~beta2-1~exp1","8.6.0~rc1-1~exp1","8.6.1-1","8.6.1-1~bpo13+1","8.6.2-1","8.6.2-1~bpo13+1","8.6.3-1","8.6.3-1~bpo13+1","8.6.4-1","8.6.4-1~bpo13+1","8.6.5-1","8.6.5-1~bpo13+1","8.6.6-1","8.6.6-1~bpo13+1"]},{"source":"osv","ecosystem":"Debian:13","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.4.0-4","8.4.0-4+deb13u1","8.4.0-4+deb13u2","8.4.1-1","8.4.1-1~bpo13+1","8.4.1-2","8.6.0-1","8.6.0-1~bpo13+1","8.6.0~beta1-1~exp1","8.6.0~beta2-1~exp1","8.6.0~rc1-1~exp1","8.6.1-1","8.6.1-1~bpo13+1","8.6.2-1","8.6.2-1~bpo13+1","8.6.3-1","8.6.3-1~bpo13+1","8.6.4-1","8.6.4-1~bpo13+1","8.6.5-1","8.6.5-1~bpo13+1","8.6.6-1","8.6.6-1~bpo13+1"]},{"source":"osv","ecosystem":"Debian:14","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.6.4-1"}]}],"versions":["8.4.0-4","8.4.1-1","8.4.1-1~bpo13+1","8.4.1-2","8.6.0-1","8.6.0-1~bpo13+1","8.6.0~beta1-1~exp1","8.6.0~beta2-1~exp1","8.6.0~rc1-1~exp1","8.6.1-1","8.6.1-1~bpo13+1","8.6.2-1","8.6.2-1~bpo13+1","8.6.3-1","8.6.3-1~bpo13+1","8.6.4-1~bpo13+1"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.0.0-4build1","7.0.0-5ubuntu1","7.0.0-7","7.0.0-8","7.0.0-8build1","7.0.0-9","7.0.0-9ubuntu1","7.0.0-9ubuntu2","7.0.0-9ubuntu3","7.0.0-9ubuntu3.1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.0.6-2build1","7.0.7-1","7.0.7-1build1","7.0.7-1build2"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.4.1-1build1","7.4.1-1build3","7.4.2-1","7.4.2-1build1","7.4.3-1","7.4.3-1build2","7.4.3-2","7.4.3-2build1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.6.3-1~exp1ubuntu1","7.6.4-2","7.6.4-2build2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.0.1-2build1","8.0.1-2build2","8.0.1-2build3","8.0.1-2build5","8.0.1-4ubuntu1","8.0.1-4ubuntu2"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"mapserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.4.0-4build1","8.4.1-1","8.4.1-1build1","8.4.1-2","8.4.1-2build1","8.6.0-1","8.6.0-1build1"]}],"products":[{"vendor":"mapserver","product":"mapserver"}],"references":[{"url":"https://github.com/MapServer/MapServer/security/advisories/GHSA-xqj6-vjqr-33vv","tags":["x_refsource_CONFIRM","exploit","advisory","report"]},{"url":"https://github.com/MapServer/MapServer/pull/7517","tags":["x_refsource_MISC","fix","report"]},{"url":"https://github.com/MapServer/MapServer/pull/7518","tags":["x_refsource_MISC","fix","report"]},{"url":"https://github.com/MapServer/MapServer/commit/edc1033c7963fcffd160d85cf430f49aaf4a1374","tags":["x_refsource_MISC","fix","report"]},{"url":"https://github.com/MapServer/MapServer/commit/ff17ef190caaeaa9002ac3d1c7969ec5315c345e","tags":["x_refsource_MISC","fix","report"]},{"url":"https://github.com/MapServer/MapServer/releases/tag/rel-8-6-4","tags":["x_refsource_MISC","web","report"]},{"url":"https://mapserver.org/development/changelog/changelog-8-6.html#changelog-8-6","tags":["x_refsource_MISC","web","report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54355.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54355","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-54355","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-54355","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-54355","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-54355","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\u0026REQUEST=GetMap\u0026FORMAT=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.","status":"published","published":"2026-09-17T20:24:32.522Z","modified":"2026-09-24T20:45:56.071Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T13:37:58.613221Z"}],"euvd":[{"id":"EUVD-2026-82433","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\u0026REQUEST=GetMap\u0026FORMAT=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.","status":"published","published":"2026-09-17T20:24:32Z","modified":"2026-09-24T20:45:56Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"updated_at":"2026-11-02T17:27:56.296478Z"}],"nvd":[{"id":"CVE-2026-54355","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\u0026REQUEST=GetMap\u0026FORMAT=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.","status":"published","published":"2026-09-17T21:17:15.41Z","modified":"2026-09-30T17:23:08.953Z","cvss":[{"version":"4.0","score":5.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:49.70655Z"}],"osv":[{"id":"CVE-2026-54355","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\u0026REQUEST=GetMap\u0026FORMAT=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.","status":"published","published":"2026-09-17T20:24:32.522Z","modified":"2026-10-28T10:52:08.426458448Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:10.818486Z"},{"id":"DEBIAN-CVE-2026-54355","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\u0026REQUEST=GetMap\u0026FORMAT=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.","status":"published","published":"2026-09-17T21:17:15.41Z","modified":"2026-10-01T08:47:40.787210687Z","cvss":[{"version":"4.0","score":5.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"}],"updated_at":"2026-11-02T15:45:57.236551Z"},{"id":"UBUNTU-CVE-2026-54355","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\u0026REQUEST=GetMap\u0026FORMAT=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.","status":"published","published":"2026-09-17T21:17:00Z","modified":"2026-09-23T23:31:21Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"updated_at":"2026-11-02T16:56:41.382716Z"}]}}