CVE-2026-84942

Stored Cross-Site Scripting via Vega Expression Function Bypass in OpenSearch Dashboards

Published Sep 8, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
Improper input validation in the Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.

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 Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.
Title Stored Cross-Site Scripting via Vega Expression Function Bypass in OpenSearch Dashboards
First Time appeared Aws
Aws amazon Opensearch Service
Opensearch
Opensearch opensearch Dashboards
Weaknesses CWE-79
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': 8.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
AMZN
Published
Updated
Sep 9, 2026, 8:51 PM
Reserved
Sep 2, 2026, 4:47 PM
Status
Awaiting Analysis
Published
Sep 8, 2026, 8:18 PM
Modified
Sep 9, 2026, 9:17 PM