CVE-2026-83351 in Database Server
Summary
by MITRE • 09/16/2026
Vulnerability in the RDBMS component of Oracle Database Server. Supported versions that are affected are 23.4.0-23.26.3. Difficult to exploit vulnerability allows unauthenticated attacker with network access via Oracle Net to compromise RDBMS. Successful attacks of this vulnerability can result in takeover of RDBMS. CVSS 3.1 Base Score 8.1 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 09/16/2026
The identified vulnerability resides within the Relational Database Management System component of Oracle Database Server, specifically affecting supported versions ranging from 23.4.0 to 23.26.3. This flaw represents a critical security deficiency that permits an unauthenticated attacker with network access via Oracle Net to compromise the integrity and availability of the database infrastructure. The severity of this issue is underscored by its CVSS 3.1 Base Score of 8.1, indicating a High level of risk due to significant impacts on confidentiality, integrity, and availability. Although the vulnerability is classified as difficult to exploit, requiring high complexity in attack execution, the potential consequence remains severe: successful exploitation allows an attacker to take full control over the RDBMS environment. This capability effectively grants the adversary administrative privileges, enabling them to manipulate data, exfiltrate sensitive information, or disrupt critical business operations dependent on the database services.
From a technical perspective, this vulnerability aligns with Common Weakness Enumeration categories such as CWE-287 Improper Authentication and CWE-94 Command Injection if code execution is involved in the takeover process. The attack vector leverages Oracle Net, which serves as the primary communication protocol for client-server interactions within the Oracle ecosystem. By exploiting flaws in how the RDBMS processes incoming network requests without proper authentication checks or input validation, an attacker can bypass standard security controls. This misconfiguration or logic error allows malicious payloads to be executed with elevated privileges, leading to a complete compromise of the database server. The high complexity required for exploitation suggests that specific conditions or precise sequence of actions are necessary, potentially involving crafted network packets or specialized tools designed to trigger the underlying flaw in the Oracle Net listener service.
The operational impact of this vulnerability is profound, as it directly threatens the core assets managed by enterprise databases. A successful takeover enables unauthorized access to all data stored within the RDBMS, including personally identifiable information, financial records, and proprietary business logic. Beyond confidentiality breaches, attackers can alter or delete critical data, leading to integrity violations that may result in regulatory non-compliance under frameworks such as GDPR, HIPAA, or PCI-DSS. Furthermore, the availability impact means that denial-of-service conditions could be induced either through resource exhaustion during exploitation or by deliberately corrupting database files post-compromise. This disrupts business continuity and can cause significant financial and reputational damage to organizations relying on Oracle Database for their mission-critical applications.
Mitigation strategies must prioritize immediate patching of all affected Oracle Database Server versions to 23.4.0-23.26.3 or later, where the vendor has presumably addressed the underlying code defects. In environments where immediate patching is not feasible due to operational constraints, network segmentation should be implemented to restrict access to Oracle Net ports from untrusted networks. Firewalls and intrusion prevention systems can be configured to monitor for anomalous traffic patterns associated with exploitation attempts of this vulnerability. Additionally, enforcing strict authentication policies and disabling unnecessary services reduces the attack surface. Security teams should also employ monitoring solutions that detect unusual privilege escalation events or unexpected administrative actions within the database logs, aligning with MITRE ATT&CK techniques such as T1078 Valid Accounts if credentials are compromised post-exploitation or T1546 Event Triggered Execution if persistence mechanisms are established. Regular vulnerability scanning and penetration testing focused on database-facing services will help identify similar weaknesses before they can be leveraged by adversaries.