AWS OpenSearch Service/Dashboards up to 3.7.x Time Series Visual Builder prototype pollution

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.4$0-$5k3.49

Summaryinfo

A vulnerability identified as critical has been detected in AWS OpenSearch Service and Dashboards up to 3.7.x. Impacted is an unknown function of the component Time Series Visual Builder. This manipulation causes prototype pollution. This vulnerability is handled as CVE-2026-18420. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability has been found in AWS OpenSearch Service and Dashboards up to 3.7.x and classified as critical. Affected by this vulnerability is some unknown functionality of the component Time Series Visual Builder. The manipulation with an unknown input leads to a prototype pollution vulnerability. The CWE definition for the vulnerability is CWE-1321. The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-18420 since 07/30/2026. The exploitation appears to be easy. The attack can be launched remotely. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1059 according to MITRE ATT&CK.

Upgrading to version 3.8.0 eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (AMZN): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Prototype pollution
CWE: CWE-1321 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: OpenSearch Service/Dashboards 3.8.0

Timelineinfo

07/30/2026 CVE reserved
08/20/2026 +21 days Advisory disclosed
08/20/2026 +0 days VulDB entry created
08/20/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-18420 (🔒)
GCVE (CVE): GCVE-0-2026-18420
GCVE (VulDB): GCVE-100-393871

Entryinfo

Created: 08/20/2026 23:13
Changes: 08/20/2026 23:13 (77)
Complete: 🔍
Cache ID: 216::103

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