CVE-2026-103009 Affecting elasticsearch-9.2-advanced-compat package, versions *

Note: Versions mentioned in the description apply only to the upstream elasticsearch-9.2-advanced-compat package and not the elasticsearch-9.2-advanced-compat package as distributed by Minimos. See How to fix? for Minimos:latest relevant fixed versions and status.

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.

• https://www.cve.org/CVERecord?id=CVE-2026-103009
• https://github.com/advisories/GHSA-jh46-59x3-g5qh
• https://osv.dev/vulnerability/MINI-wpc9-448m-6fx5
• https://osv.dev/vulnerability/CVE-2026-103009
• https://discuss.elastic.co/t/elasticsearch-8-19-23-9-4-8-9-5-5-security-update-esa-2026-199/390874