8.7

CVE-2026-84942: opensearch opensearch dashboards Cross-site Scripting

CVSS: 8.7v3.1HighAwaiting analysis
Published 08-09-2026Last modified 09-09-2026
Open JSON

Vulnerability summary

CVE-2026-84942 is a high (CVSS 8.7) Cross-site Scripting vulnerability in opensearch opensearch dashboards. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.8% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v3.1 (CVE.org)
EPSS score
0.54%
0%100%
Low · +0.21 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 08-09-2026
    PublishedVulnerability first disclosed.
  2. 09-09-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.54%

Chance of exploitation in the next 30 days

Percentile

45%

Versus all other CVEs

30-day change

+0.21 pp

From 0.33% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.54%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Opensearch1 product

1 vendor · 1 product

References

3 links