CVE-2026-84942Network attack vector

Stored XSS via nested Vega function property

Published Sep 8, 2026 · Updated Sep 9, 2026

Stored XSS in OpenSearch Dashboards 2.0.0 through 3.5.0 allows remote authenticated users to run JavaScript via crafted Vega visualizations. The checkForFunctionProperty routine validates object properties but fails to recurse into arrays of objects, so a nested function property passes validation. Dashboard write permission is required, and the saved payload executes in other users' browser sessions when the visualization is viewed.

CVSS severityUnavailable
Unscored
EPSS probability0.33%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Stored XSS in OpenSearch Dashboards 2.0.0 through 3.5.0 allows remote authenticated users to run JavaScript via crafted Vega visualizations. The checkForFunctionProperty routine validates object properties but fails to recurse into arrays of objects, so a nested function property passes validation. Dashboard write permission is required, and the saved payload executes in other users' browser sessions when the visualization is viewed.

The record

CVE
CVE-2026-84942
Published
Sep 8, 2026
Updated
Sep 9, 2026
Vendor
OpenSearch Software Foundation
Product
OpenSearch Dashboards
Classifications
T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=v2.0.0 <=v3.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenSearch Software Foundation · OpenSearch Dashboardsversion=v2.0.0 <=v3.5.0

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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