Oracle published the pre-release announcement for the October 2026 Critical Patch Update on Thursday, October 15. The full CPU ships Tuesday, October 20, 2026, and it includes a large Siebel CRM batch.

October 2026 CPU — Siebel CRM

123 new security patches for Oracle Siebel CRM.
67 of them may be remotely exploitable without authentication.
Highest CVSS v3.1 base score: 9.9.
Affected: Siebel Applications versions 17.0 through 26.9.
Also in scope: Oracle Enterprise Manager for Siebel, versions 13.5 and 24.1.

Pre-release details can change before the final advisory on October 20. Siebel teams should line up a non-production test window this week and plan production patching soon after the advisory is final.

Source: https://www.oracle.com/security-alerts/cpuoct2026.html

Also new: OpenSearch 3.2 support for Siebel Intelligent Search

Oracle's Siebel product blog (October 6) confirmed OpenSearch 3.2.0 support for Siebel Intelligent Search with Siebel CRM 26.9 and later. OpenSearch 2.15.0 remains supported from 25.10, so existing deployments don't have to move right away. Updated OpenSearch auto-install scripts are available as patch 39116180 through a Service Request to Siebel Support. The OpenSearch version in modernsearchconfig.yaml must exactly match the installed version.

Source: https://blogs.oracle.com/siebelcrm/siebel-intelligent-search-adds-opensearch-3-2-support-in-siebel-crm-26-9

Siebel CRM 26.9 remains the latest monthly update; there's no 26.10 release yet.