RCE in Cesiumgs Cesiumjs
CVE-2026-3990
A security flaw has been discovered in CesiumGS CesiumJS up to 1.137.0. Affected by this issue is some unknown functionality of the file Apps/Sandcastle/standalone.html. The manipulation of the argument c results in cross site scripting. The attack can be launched remotely. The exploit has been released to the public and may be used for attacks. The presence of this vulnerability remains uncertain at this time. The vendor was contacted early about this disclosure but did not respond in any way. According to CVE-2023-48094, "the vendor's position is that Apps/Sandcastle/standalone.html is part of the CesiumGS/cesium GitHub repository, but is demo code that is not part of the CesiumJS JavaScript library product."
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.003 (18.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.
Affected products
- Cesiumgs Cesiumjs — versions 1.137
Weakness classification (CWE)
References
- cna@vuldb.com (technical-description, vdb-entry)
- cna@vuldb.com (signature, permissions-required)
- cna@vuldb.com (third-party-advisory)
- cna@vuldb.com (issue-tracking, exploit)
Frequently asked questions
- What is CVE-2026-3990?
- CVE-2026-3990 is a medium-severity vulnerability in Cesiumgs Cesiumjs, classified under Cross-site Scripting. CVSS score: 4.3/10. Published 2026-03-12.
- How severe is CVE-2026-3990?
- Medium severity. CVSS v3 base score is 4.3 out of 10.