CVE-2026-49294 json
Valhalla has reflected XSS via unsanitized JSONP callback parameter
published 2026-06-15 4 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-36741
- cvss
- 6.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 4%
- public exploits
- 0
- none known
Summary
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 <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.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/valhalla/valhalla/security/advisories/GHSA-85xx-39j8-r56x referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected products
- valhalla valhalla
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
Sources
- CVE List CVE-2026-49294
- NVD CVE-2026-49294
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