amazon aws CVE-2026-84942 in Amazon and Opensearch Products
Published on September 8, 2026

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

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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.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-84942 is exploitable with network access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
REQUIRED
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
NONE

Weakness Type

What is a XSS Vulnerability?

The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

CVE-2026-84942 has been classified to as a XSS vulnerability or weakness.


Products Associated with CVE-2026-84942

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Amazon Aws
 
Opensearch Dashboards
 

Affected Versions

AWS Amazon OpenSearch Service: OpenSearch Dashboards: