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.
History

Fri, 09 Oct 2026 13:30:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:*:*:*

Fri, 09 Oct 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Tue, 06 Oct 2026 23:30:00 +0000

Type Values Removed Values Added
First Time appeared Elastic
Elastic elasticsearch
Vendors & Products Elastic
Elastic elasticsearch

Tue, 06 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 06 Oct 2026 19:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Authorization Bypass Through User-Controlled Key in Elasticsearch Leading to Information Disclosure
Weaknesses CWE-639
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: elastic

Published: 2026-10-06T19:31:53.261Z

Updated: 2026-10-06T19:52:13.370Z

Reserved: 2026-09-29T20:57:38.467Z

Link: CVE-2026-103009

cve-icon Vulnrichment

Updated: 2026-10-06T19:52:10.160Z

cve-icon NVD

Status : Analyzed

Published: 2026-10-06T20:17:14.247

Modified: 2026-10-09T13:13:05.053

Link: CVE-2026-103009

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-06T19:31:53Z

Links: CVE-2026-103009 - Bugzilla