CVE-2026-18420

EUVD-2026-63592
Improper input validation in the Time Series Visual Builder (TSVB) plugin in OpenSearch Dashboards allows an authenticated remote user to execute arbitrary code on the server via a crafted JSON payload to the metrics visualization API endpoint. This issue is a form of prototype pollution that enables remote code execution. 



To remediate this issue, users should upgrade to OpenSearch Dashboards 3.8 or later.
Prototype Pollution
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
8.8 HIGH
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Common Weakness Enumeration
References
https://aws.amazon.com/security/security-bulletins/2026-085-aws/
https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/3.8.0
https://github.com/opensearch-project/OpenSearch-Dashboards/security/advisories/GHSA-xmqx-xq2p-8jq2