CVE-2026-84942

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.

CVSS v3 8.7 HIGH

8.7^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.3 / Impact : 5.8

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://aws.amazon.com/security/security-bulletins/2026-102-aws/
https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/2.19.5
https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/3.6.0

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-08 20:18

Updated : 2026-09-09 21:17

NVD link : CVE-2026-84942

Mitre link : CVE-2026-84942

CVE.ORG link : CVE-2026-84942

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

{"id": "CVE-2026-84942", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-84942", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-09-09T20:45:08.722192Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.7, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.8, "exploitabilityScore": 2.3}], "cvssMetricV40": [{"type": "Secondary", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 6.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "PASSIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "subIntegrityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "affectedData": [{"vendor": "AWS", "product": "Amazon OpenSearch Service", "versions": [{"status": "unaffected", "version": "v2.3.0", "versionType": "custom", "lessThanOrEqual": "v3.5.0"}], "defaultStatus": "unaffected"}, {"vendor": "OpenSearch", "product": "OpenSearch Dashboards", "versions": [{"status": "affected", "version": "v2.0.0", "versionType": "custom", "lessThanOrEqual": "v3.5.0"}], "defaultStatus": "unaffected"}]}], "published": "2026-09-08T20:18:51.307", "references": [{"url": "https://aws.amazon.com/security/security-bulletins/2026-102-aws/", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5"}, {"url": "https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/2.19.5", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5"}, {"url": "https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/3.6.0", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "description": [{"lang": "en", "value": "CWE-79"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-09-09T21:17:05.473", "sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5"}