CVE-2026-18420

highCVSS 8.8covered by 2 sourcesfirst seen 2026-08-20

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.

CSIRTS triage

What: Improper input validation in Time Series Visual Builder (TSVB) plugin allows remote authenticated code execution via crafted JSON payload.
Who is affected: OpenSearch Dashboards users (self-managed and AWS-managed) on versions 3.0.0 through 3.7.x with standard data access permissions.
Urgency: Critical; authenticated RCE in widely-used visualization plugin requires immediate patching.
Action: Upgrade OpenSearch Dashboards to version 3.8.0 or later.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Low exploitation risk0.96% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 58% of all EPSS-scored CVEs.

Advisory coverage (2)

unknownCVE-2026-18420 - Remote Code Execution via Prototype Pollution in OpenSearch Dashboards TSVB Pluginaws · 2026-08-20
highCVE-2026-18420: Improper input validation in the Time Series Visual Builder (TSVB) plugin in OpenSearch Dashbo…nvd · 2026-08-20

External references

NVD record for CVE-2026-18420

CVE.org record

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