CVE-2026-47040 Oracle CVE debrief

Who should care

Oracle Database Server administrators, security teams, and IT professionals responsible for maintaining and securing Oracle Database Server instances should be aware of this vulnerability and take immediate action to mitigate its risks.

Technical summary

The CVE-2026-47040 vulnerability affects the Oracle Net Services component of Oracle Database Server. It is easily exploitable by unauthenticated attackers with network access via Oracle Net, potentially leading to unauthorized access to critical data and complete access to all Oracle Net Services accessible data, as well as the unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Net Services. The CVSS 3.1 Base Score is 9.1, indicating critical severity, with Confidentiality and Availability impacts.

Defensive priority

Oracle Database Server users should prioritize patching this vulnerability due to its critical CVSS score of 9.1 and potential for unauthorized data access and service disruption.

Recommended defensive actions

• Apply patches or updates provided by Oracle to vulnerable versions of Database Server
• Restrict network access to Oracle Net Services to minimize exposure
• Monitor for suspicious activity related to Oracle Net Services
• Review and update inventory of Oracle Database Server instances to ensure accurate tracking of affected systems
• Consider implementing compensating controls, such as additional authentication or access restrictions, until patches can be applied

Evidence notes

The CVE-2026-47040 vulnerability affects Oracle Database Server versions 19.3-19.31, 21.3-21.22, and 23.4.0-23.26.2. It allows unauthenticated attackers with network access via Oracle Net to compromise Oracle Net Services, potentially leading to unauthorized data access and service disruption. The CVSS 3.1 Base Score is 9.1, indicating critical severity.

Official resources