RCE via Prototype Pollution in OpenSearch Dashboards

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-18420
StatePUBLISHED
AssignerAMZN
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-20 21:17:06 UTC
Updated2026-08-20 21:17:06 UTC
DescriptionImproper input validation in the Time Series Visual Builder (TSVB) plugin in OpenSearch Dashboards allows an authenticated remote user to execute arbitrary code on the server via a crafted JSON payload to the metrics visualization API endpoint. This issue is a form of prototype pollution that enables remote code execution.  To remediate this issue, users should upgrade to OpenSearch Dashboards 3.8 or later.

Risk And Classification

Primary CVSS: v4.0 8.7 HIGH from ff89ba41-3aa1-4d27-914a-91399e9639e5

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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

Problem Types: CWE-1321 | CWE-1321 CWE-1321 Improperly controlled modification of object prototype attributes ('prototype pollution')

VersionSourceTypeScoreSeverityVector
4.0ff89ba41-3aa1-4d27-914a-91399e9639e5Secondary8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
3.1ff89ba41-3aa1-4d27-914a-91399e9639e5Secondary8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNACVSS8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA AWS Amazon OpenSearch Service affected 3.0.0 3.8.0 custom Not specified
CNA OpenSearch OpenSearch Dashboards affected 3.0.0 3.8.0 custom Not specified

References

ReferenceSourceLinkTags
aws.amazon.com/security/security-bulletins/2026-085-aws ff89ba41-3aa1-4d27-914a-91399e9639e5 aws.amazon.com
github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/3.8.0 ff89ba41-3aa1-4d27-914a-91399e9639e5 github.com
github.com/opensearch-project/OpenSearch-Dashboards/security/advisories/... ff89ba41-3aa1-4d27-914a-91399e9639e5 github.com
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