CVE-2026-84942

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

Published: Sep 8, 2026Updated: Sep 9, 2026 Sources: CVE List NVDCWE-79

8.7HIGH

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:LPrivileges Required

Low

UI:RUser Interaction

Required

Scope

S:CScope

Changed

Impact

C:HConfidentiality

High

I:HIntegrity

High

A:NAvailability

None

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Weaknesses

CWE-79

Affected Products

AWS

commercial·US

Amazon OpenSearch ServiceMixed

Cloud & SaaS / cloud-platform

OpenSearch

oss-project·US

OpenSearch DashboardsOn-prem

Databases / db-tooling

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Execution

Initial Access

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References

https://aws.amazon.com/security/security-bulletins/2026-102-aws/

aws.amazon.com

https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/2.19.5

github.com

https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/3.6.0

github.com

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