CVE-2026-84942

HIGHPre-NVD 8.78.7—
EchelonGraph scoreHIGH confidence

Score 8.7 from GitHub Security Advisory published 2026-09-08. a secondary CVSS source baseline 8.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
8.7
EG Score
8.7(high)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
27%
KEV
Not listed

Published

September 8, 2026

Last Modified

September 9, 2026

Advisory Details (2)

Auto-updated Sep 8, 2026
Patch available. Sources: github_release.
generic

CVE-2026-84942 - Stored Cross-Site Scripting via Vega Expression Function Bypass in OpenSearch Dashboards

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

3.6.0

Patch available: opensearch-project/OpenSearch-Dashboards 3.6.0

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

Vendor Advisories for CVE-2026-84942(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 26× in last 7d / 45× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 21:36 UTCEG score recompute
  2. 2026-09-18 21:36 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 08:57 UTCGHSA enrichment
  5. 2026-09-17 20:17 UTCEG score recompute
  6. 2026-09-17 20:17 UTCGHSA enrichment
  7. 2026-09-17 19:32 UTCEPSS rescore
  8. 2026-09-17 06:56 UTCGHSA enrichment
  9. 2026-09-16 18:16 UTCEG score recompute
  10. 2026-09-16 18:16 UTCGHSA enrichment
  11. 2026-09-16 14:09 UTCEPSS rescore
  12. 2026-09-16 05:36 UTCEG score recompute
  13. 2026-09-16 05:36 UTCGHSA enrichment
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 16:57 UTCGHSA enrichment
  16. 2026-09-15 04:17 UTCEG score recompute
  17. 2026-09-15 04:17 UTCGHSA enrichment
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-15 03:12 UTCEPSS rescore
  20. 2026-09-14 15:37 UTCGHSA enrichment
  21. 2026-09-14 02:57 UTCEG score recompute
  22. 2026-09-14 02:57 UTCGHSA enrichment
  23. 2026-09-13 14:18 UTCGHSA enrichment
  24. 2026-09-13 01:38 UTCEG score recompute
  25. 2026-09-13 01:38 UTCGHSA enrichment
Show 20 more
  1. 2026-09-12 12:58 UTCGHSA enrichment
  2. 2026-09-12 00:19 UTCEG score recompute
  3. 2026-09-12 00:19 UTCGHSA enrichment
  4. 2026-09-11 14:53 UTCEPSS rescore
  5. 2026-09-11 14:53 UTCEPSS rescore
  6. 2026-09-11 11:39 UTCEG score recompute
  7. 2026-09-11 11:39 UTCGHSA enrichment
  8. 2026-09-10 22:52 UTCGHSA enrichment
  9. 2026-09-10 10:12 UTCEG score recompute
  10. 2026-09-10 10:12 UTCGHSA enrichment
  11. 2026-09-09 21:32 UTCEG score recompute
  12. 2026-09-09 21:32 UTCGHSA enrichment
  13. 2026-09-09 20:55 UTCEG score recompute
  14. 2026-09-09 20:55 UTCGHSA enrichment
  15. 2026-09-09 16:02 UTCGHSA enrichment
  16. 2026-09-09 09:17 UTCEG score recompute
  17. 2026-09-09 09:17 UTCGHSA enrichment
  18. 2026-09-08 20:37 UTCEG score recompute
  19. 2026-09-08 19:50 UTCEG score recompute
  20. 2026-09-08 19:49 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84942?
CVE-2026-84942 is a high vulnerability published on September 8, 2026. 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…
When was CVE-2026-84942 disclosed?
CVE-2026-84942 was first published in the National Vulnerability Database on September 8, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84942 actively exploited?
CVE-2026-84942 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 73.3% of all scored CVEs.
What is the CVSS score of CVE-2026-84942?
CVE-2026-84942 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-84942?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84942, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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