CVE-2026-49294
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedValhalla 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 <script src="..."> tag, the injected script executes in the context of the serving origin, potentially leading to session token theft, credential disclosure, or actions performed on behalf of the victim. This issue was not fixed at time of publication.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceValhalla routing engine versions 3.6.3 and prior contain a reflected XSS vulnerability in the JSONP callback parameter. When a request includes a JSONP callback, the value is directly reflected into the HTTP response with Content-Type: application/javascript without any validation, output encoding, or allowlist filtering. An attacker can inject arbitrary JavaScript that executes in the context of the serving origin when victims load the crafted URL via a script tag.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Valhalla installation and versionLocate the Valhalla routing engine installation and determine its version number. Common methods include checking the binary or service version flag, or reviewing package/dependency documentation.Affected if The installed version is 3.6.3 or any earlier version.
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Confirm JSONP endpoint is accessibleIdentify whether the Valhalla service exposes an API endpoint that accepts a JSONP callback parameter. This is typically a route handling API requests that may return JavaScript content.Affected if JSONP callback functionality is enabled and accessible on the service.
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Test callback parameter for reflected XSSSend a request to a Valhalla API endpoint with a crafted callback parameter containing a test XSS payload (such as a simple alert or script tag). Inspect the HTTP response to verify the payload is reflected unescaped and the Content-Type is application/javascript.Affected if The callback value is reflected verbatim in the response without sanitization or encoding.
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Verify script execution contextConfirm the response Content-Type header is set to application/javascript, which enables the browser to execute the reflected content as script when loaded via a script tag.Affected if The response Content-Type is application/javascript and the injected payload is present in the response body.
A user is affected if they run Valhalla version 3.6.3 or earlier, have JSONP callback functionality exposed, and the callback parameter reflects unsanitized input in responses served as application/javascript.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement strict allowlist filtering for the JSONP callback parameter (restrict to alphanumeric characters only) and apply proper output encoding, or migrate away from JSONP to CORS-based APIs which do not enable script execution via cross-origin requests.
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-49294 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-49294 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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