Vulnerability in Elasticsearch

[ Description ]Official description

Incorrect Authorization (CWE-863) in Elasticsearch can lead to unauthorized data stream modification via Accessing Functionality Not Properly Constrained by ACLs (CAPEC-1). An authenticated user with sufficient privileges over a single resource could use the Modify Data Streams API to modify a data stream to which they were not otherwise authorized, potentially injecting data into it or affecting its ability to be searched normally. This issue does not allow an attacker to read the contents of a data stream they do not otherwise have access to.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• CERT-FR7 Oct 2026CERTFR-2026-AVI-1276

  Multiple vulnerabilities in Elastic products Translated from French

  Multiple vulnerabilities have been discovered in Elastic products. Some of them allow an attacker to cause privilege escalation, a breach of data confidentiality and a security policy bypass.

  CVE-2026-102406CVE-2026-103006CVE-2026-102404+11 more CVEs
• BSI CERT-Bund6 Oct 2026WID-SEC-2026-3784

  Elasticsearch: Multiple vulnerabilities Translated from German

  CVE-2026-102404CVE-2026-103005CVE-2026-103006+7 more CVEs

[ References ]References

• discuss.elastic.co/t/elasticsearch-8-19-19-9-3-8-9-4-4-security-update-esa-2026-188/390861Vendor Advisory