Valhalla is an open source routing engine and accompanying libraries for use with OpenStreetMap data. Versions 3.6.3 and prior are vulnerable to reflected cross-site scripting (XSS) due to improper neutralization of input in the JSONP callback parameter. When a request specifies a JSONP callback, the value is reflected directly into the HTTP response body with Content-Type: application/javascript, without any validation, output encoding, or allowlist filtering. An attacker can craft a URL containing arbitrary JavaScript in the callback parameter; if a victim is induced to load that URL via a
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-79"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49294.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"last_affected": "3.6.3"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"introduced": "0"
},
{
"last_affected": "3.6.3"
}
],
"source": "DESCRIPTION"
}
]
}