CVE-2026-84942

medium

Description

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.

References

https://aws.amazon.com/security/security-bulletins/2026-102-aws/

https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/3.6.0

https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/2.19.5

Details

Source: Mitre, NVD

Published: 2026-09-08

Updated: 2026-09-09

Risk Information

CVSS v2

Base Score: 8.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 8.7

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

Severity: High

CVSS v4

Base Score: 6.3

Vector: 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

Severity: Medium

EPSS

EPSS: 0.00333