CVE-2026-103009 Elasticsearch - Authorization Bypass

Elasticsearch contains an authorization bypass caused by inconsistent shard identifier validation in cross-cluster search requests using Remote Cluster Security 2.0, letting attackers with cross-cluster API keys access unauthorized index data, exploit requires crafted cross-cluster search requests with mismatched shard identifiers.

CVSS base score 7.1 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
0.23% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Authorization Bypass
Impact
Information Disclosure, Data Tampering
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Published
6 October 2026
Updated
15 October 2026
Weakness
CWE-639

Vendor fix

Update to the latest Elasticsearch version with Remote Cluster Security 2.0 fixes.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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