{
  "cveId": "CVE-2026-54355",
  "url": "https://patchblox.com/security/cve/CVE-2026-54355",
  "summary": "CVE-2026-54355 is fixed in mapserver on 1 platform by DEBIAN-CVE-2026-54355 (version 8.6.4-1), released September 21, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "mapserver: MapServer is a system for developing web-based GIS applications",
  "description": "MapServer is a system for developing web-based GIS applications. From 6.0 until 8.6.4, MapServer\u0027s 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.",
  "published": "2026-09-17T21:17:15Z",
  "severity": "",
  "epss": 0.005,
  "epssPercentile": 0.43088,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "mapserver",
      "release": "Debian 14",
      "fixedVersion": "8.6.4-1",
      "fix": "DEBIAN-CVE-2026-54355",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-54355",
      "released": "2026-09-21T18:54:34Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}