# CVE-2026-103009 — Elastic Elasticsearch

> As of 2026-10-06, CVE-2026-103009 is a HIGH-severity vulnerability in Elastic Elasticsearch, CVSS v3.1 7.1, EPSS 0.2% (12.8th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-103009, most recently “Elastic Patches 14 Security Flaws Including Kibana Cross-Tenant Data Interception (CVE-2026-102406)”.

**Last updated:** 2026-10-06

## What is CVE-2026-103009?

Authorization Bypass Through User-Controlled Key (CWE-639) in Elasticsearch can lead to Information Disclosure via a specially crafted cross-cluster search request that references an unauthorized shard identifier. Elasticsearch contains an authorization bypass weakness in its handling of cross-cluster search requests made through the Remote Cluster Security (RCS) 2.0 model. An authorization check validates a request against one identifying attribute of the target shard, while a separate, independently-supplied identifying attribute in the same request determines which shard is actually accessed. A holder of a cross-cluster API key authorized for one index can craft a request whose two identifying attributes refer to different indices, causing the request to be authorized against an index they can access while actually operating against a different, unauthorized index. This can expose that index's document contents, field mappings, and other metadata, and in limited cases allows modification of retention-lease state on the unauthorized index.

The record classifies CVE-2026-103009 under weakness class [CWE-639](https://intel.threadlinqs.com/cwe/CWE-639). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 4 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.1 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N`)
- **EPSS (FIRST):** 0.2% probability of exploitation in the next 30 days, higher than 12.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.1/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-10-06

## Is CVE-2026-103009 being exploited?

It currently carries a trending score of 37 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Elastic](https://intel.threadlinqs.com/vendors/elastic): Elasticsearch

## How to fix CVE-2026-103009

No vendor patch reference has been recorded for CVE-2026-103009 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-103009

1 tracked threat in the Threadlinqs corpus references CVE-2026-103009, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Elastic Patches 14 Security Flaws Including Kibana Cross-Tenant Data Interception (CVE-2026-102406)](https://intel.threadlinqs.com/threat/TL-2026-3268) — HIGH · 2026-10-10

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [discuss.elastic.co](https://discuss.elastic.co/t/elasticsearch-8-19-23-9-4-8-9-5-5-security-update-esa-2026-199/390874)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-103009
Full detection coverage and IOCs for threats exploiting CVE-2026-103009 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp