CVE-2026-18420

RCE via Prototype Pollution in OpenSearch Dashboards

Published Aug 20, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title RCE via Prototype Pollution in OpenSearch Dashboards
First Time appeared Aws
Aws amazon Opensearch Service
Opensearch
Opensearch opensearch Dashboards
Weaknesses CWE-1321
CPEs cpe:2.3:a:aws:amazon_opensearch_service:*:*:*:*:*:*:*:*
cpe:2.3:a:opensearch:opensearch_dashboards:*:*:*:*:*:*:*:*
Vendors & Products Aws
Aws amazon Opensearch Service
Opensearch
Opensearch opensearch Dashboards
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
AMZN
Published
Updated
Aug 25, 2026, 7:19 PM
Reserved
Jul 30, 2026, 6:11 PM
Status
Awaiting Analysis
Published
Aug 20, 2026, 9:17 PM
Modified
Oct 26, 2026, 10:10 AM