CVE-2026-83189 in User Management
Summary
by MITRE • 09/16/2026
Vulnerability in the Oracle User Management product of Oracle E-Business Suite (component: Proxy User Delegation). Supported versions that are affected are 12.2.3-12.2.15. Easily exploitable vulnerability allows low privileged attacker with network access via HTTP to compromise Oracle User Management. Successful attacks of this vulnerability can result in takeover of Oracle User Management. CVSS 3.1 Base Score 8.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/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 Proxy User Delegation component of Oracle User Management in Oracle E-Business Suite, specifically affecting versions ranging from 12.2.3 through 12.2.15. This security flaw represents a critical weakness in the authentication and authorization mechanisms that govern how user privileges are delegated across system boundaries. The core technical issue involves an insufficient validation of proxy delegation requests, allowing attackers to manipulate session contexts or escalate their privilege levels beyond what is legitimately assigned by administrative policies. By exploiting this logic error, an attacker can bypass standard access controls intended to restrict low-privileged users from performing high-level administrative actions or accessing sensitive data stores that are normally protected behind stricter authentication gates.
From a technical perspective, the vulnerability leverages network-accessible HTTP endpoints associated with the User Management service. Because the flaw is easily exploitable and requires no user interaction, it falls squarely into the category of remote code execution or privilege escalation via improper access control mechanisms. The attacker needs only low-privileged credentials to initiate the attack vector, which significantly lowers the barrier for entry compared to vulnerabilities requiring administrative rights or complex social engineering tactics. Once exploited, the malicious actor gains the ability to impersonate higher-level users or manipulate session tokens in a way that grants them unauthorized control over critical system functions. This aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-269 Improper Privilege Management and CWE-732 Incorrect Permission Assignment for Critical Resource, highlighting the fundamental failure to enforce least privilege principles during proxy delegation operations.
The operational impact of this vulnerability is severe, characterized by a CVSS 3.1 Base Score of 8.8, indicating high severity across all three pillars of the security triad: confidentiality, integrity, and availability. The attack vector allows for complete takeover of the Oracle User Management subsystem, which serves as the central hub for identity management within the E-Business Suite environment. Compromise of this component enables an attacker to exfiltrate sensitive employee data, customer records, or financial information stored in associated databases, thereby breaching confidentiality requirements under regulations such as GDPR or HIPAA if applicable. Furthermore, the integrity impact is substantial because the attacker can modify user roles, create backdoor accounts, or alter permission sets, effectively maintaining persistent access and evading detection by security monitoring tools that rely on standard audit logs for anomaly detection. The availability aspect stems from the potential to disrupt service operations through malicious account modifications or resource exhaustion attacks facilitated by elevated privileges.
In terms of threat modeling and adversary behavior, this vulnerability maps directly to MITRE ATT&CK techniques related to Initial Access via Valid Accounts and Privilege Escalation. An attacker would likely utilize automated scanning tools to identify vulnerable instances before launching targeted exploitation attempts against the HTTP endpoints exposed by the User Management service. The lack of required user interaction means that once network access is established, whether through direct internet exposure or lateral movement within a compromised internal network, the exploit can be executed rapidly without alerting end-users. This stealthiness increases the risk of prolonged undetected presence in the environment, allowing for deeper infiltration and data staging before remediation efforts are initiated by security operations teams.
Mitigation strategies must prioritize immediate patching to address the underlying code defects responsible for the improper delegation logic. Organizations running affected versions should apply the latest Oracle Critical Patch Update (CPU) that specifically targets this vulnerability as soon as possible, ensuring compatibility with existing customizations and integrations within their E-Business Suite landscape. In scenarios where immediate patching is not feasible due to operational constraints or testing requirements, temporary compensating controls are essential. These include restricting network access to the Oracle User Management HTTP endpoints by implementing strict firewall rules that limit connectivity only to trusted application servers and administrative workstations. Additionally, enabling enhanced logging and monitoring for unusual patterns in proxy delegation requests can help detect exploitation attempts in real-time. Security teams should also review existing user roles and permissions to ensure no excessive privileges are granted to low-level accounts, thereby reducing the potential blast radius if a similar vulnerability were to be discovered or exploited via alternative vectors. Regular audits of authentication logs and periodic penetration testing focused on identity management components will further strengthen the defense-in-depth posture against such privilege escalation threats.