A high-severity vulnerability exists in the Siebel CRM Deployment product of Oracle Siebel CRM, specifically in the Server Infrastructure component. This vulnerability affects supported versions from 17.0 through 26.7. It allows a low-privileged attacker with network access via HTTPS to compromise the Siebel CRM Deployment, potentially resulting in full takeover. The CVSS 3.1 base score is 8.8, indicating high impact on confidentiality, integrity, and availability. Oracle has included a fix for this vulnerability in its September 2026 Critical Security Patch Update.