CVE-2026-83039 in WebCenter Portal
Summary
by MITRE • 09/16/2026
Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Composer). Supported versions that are affected are 12.2.1.4.0 and 14.1.2.0.0. Easily exploitable vulnerability allows low privileged attacker with network access via HTTP to compromise Oracle WebCenter Portal. While the vulnerability is in Oracle WebCenter Portal, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in takeover of Oracle WebCenter Portal. CVSS 3.1 Base Score 9.9 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 09/16/2026
The identified vulnerability resides within the Composer component of Oracle WebCenter Portal, a key element of the Oracle Fusion Middleware suite. This security flaw affects specific supported versions, namely 12.2.1.4.0 and 14.1.2.0.0, indicating that even recently maintained releases are susceptible to exploitation. The nature of this vulnerability is particularly concerning due to its high ease of exploitability combined with a low barrier for entry regarding attacker privileges. Specifically, the flaw allows an attacker who possesses only low-level user credentials and has network access via HTTP to successfully compromise the Oracle WebCenter Portal application. This characteristic significantly lowers the threshold for potential malicious actors, as it does not require administrative rights or complex social engineering tactics to initiate an attack vector against the system.
The operational impact of this vulnerability is severe, characterized by a complete takeover of the affected Oracle WebCenter Portal instance. The CVSS 3.1 base score of 9.9 reflects critical severity across all three pillars of security: confidentiality, integrity, and availability. This high scoring indicates that successful exploitation can lead to unauthorized access to sensitive data, modification or destruction of system configurations and content, and disruption of service for legitimate users. Furthermore, the vulnerability exhibits a scope change behavior, meaning that while the technical flaw is located within Oracle WebCenter Portal, the consequences extend beyond this specific product boundary. Attacks leveraging this weakness may significantly impact additional products within the broader Oracle Fusion Middleware ecosystem or connected systems, thereby amplifying the blast radius of a single successful exploit and complicating containment efforts for security operations teams.
From a classification perspective, this vulnerability aligns with CWE-79, which covers Cross-Site Scripting (XSS) vulnerabilities often found in web application components like Composer that handle user input or render content dynamically. The ability to take over the portal suggests potential privilege escalation mechanisms or insecure direct object references being exploited within the composer interface. In terms of adversary tactics, this aligns with MITRE ATT&CK techniques related to Initial Access via valid accounts and subsequent Execution or Persistence depending on how the takeover is utilized. Attackers could use this foothold to inject malicious scripts, steal session cookies for credential theft, or manipulate portal configurations to create backdoors that persist even after initial access is detected.
Mitigation strategies must prioritize immediate remediation given the high severity and ease of exploitation. Organizations running affected versions should apply the latest security patches provided by Oracle as soon as they are available in their respective release channels. Until patching can be implemented, network-level controls such as Web Application Firewalls (WAF) should be configured to detect and block patterns associated with this specific vulnerability's exploit code. Access control policies must also be reviewed to ensure that low-privileged users have the minimum necessary permissions within the Composer component, reducing the attack surface available to potential intruders. Additionally, monitoring for anomalous HTTP traffic targeting the Composer endpoints can help in early detection of exploitation attempts before full system compromise occurs.