CVE-2026-18420 PUBLISHED

RCE via Prototype Pollution in OpenSearch Dashboards

Assigner: AMZN
Reserved: 30.07.2026 Published: 20.08.2026 Updated: 20.08.2026

Improper 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.

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.8

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

CVSS 3.1

CVSS Vector: 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
CVSS Score: 8.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	AWS
Product	Amazon OpenSearch Service
Versions	Default: unaffected affected from 3.0.0 to 3.8.0 (excl.)

Vendor	OpenSearch
Product	OpenSearch Dashboards
Versions	Default: unaffected affected from 3.0.0 to 3.8.0 (excl.)

References

Problem Types

CWE-1321 Improperly controlled modification of object prototype attributes ('prototype pollution') CWE

Impacts

CAPEC-586 Object Injection