CVE-2026-101515 in WebLogic Server
Summary
by MITRE • 10/21/2026
Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Centralized Thirdparty Jars). Supported versions that are affected are 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0 and 15.1.1.0.0. Difficult to exploit vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle WebLogic Server accessible data. CVSS 3.1 Base Score 5.9 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).
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Analysis
by VulDB Data Team • 10/21/2026
The identified vulnerability resides within the Centralized Thirdparty Jars component of Oracle WebLogic Server, a critical enterprise application server used for deploying and managing Java-based applications across various industries. This flaw affects multiple supported versions including 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0, and 15.1.1.0.0. The core issue stems from improper handling of input data within the third-party libraries bundled with or utilized by WebLogic Server. These dependencies often contain complex logic for parsing requests, managing sessions, or processing serialized objects. When an attacker sends specifically crafted HTTP requests to the server, they can trigger a flaw in how these jars process the incoming data. Although the vulnerability is classified as difficult to exploit due to high complexity requirements and specific environmental conditions, its existence poses a significant risk because it does not require any prior authentication. This means that any external actor with network access to the WebLogic Server instance can attempt to leverage this weakness without needing valid credentials or user interaction.
From an operational perspective, the impact of successfully exploiting this vulnerability is severe regarding data confidentiality. The CVSS 3.1 base score of 5.9 reflects a medium severity rating driven primarily by high impacts on confidentiality while integrity and availability remain unaffected in the baseline vector. Successful exploitation allows an unauthenticated attacker to gain unauthorized access to critical data stored or processed by the WebLogic Server environment. This could include sensitive business logic, customer information, internal configurations, or proprietary application state data. In worst-case scenarios where the server is configured with broader permissions or serves as a gateway to backend databases, this initial foothold can lead to complete access to all Oracle WebLogic Server accessible data. The lack of authentication requirements makes this particularly dangerous in internet-facing deployments where automated scanning tools are constantly probing for entry points.
This vulnerability aligns with CWE-20 Improper Input Validation and potentially CWE-749 Exposed Dangerous Method if the flaw involves invoking unsafe operations through reflection or dynamic class loading within the third-party jars. In terms of offensive security frameworks, this behavior is consistent with ATT&CK technique T1190 Exploit Public-Facing Application, where attackers target vulnerabilities in software services exposed to the network. The high complexity and difficulty to exploit suggest that while automated mass exploitation may be less common than for critical remote code execution flaws, targeted attacks by skilled adversaries remain a viable threat vector. Attackers might use this vulnerability as part of a multi-stage attack chain to gather intelligence or establish persistence before moving laterally within the network.
Mitigation strategies should focus on immediate patching and configuration hardening. Oracle has likely released security patches for these specific versions that address the input validation flaws in the third-party jars. Administrators must apply the latest available updates from Oracle Support immediately, ensuring they verify compatibility with their existing application deployments to avoid service disruption during the update process. In environments where patching is not immediately feasible due to operational constraints, network-level controls should be implemented as compensating measures. This includes restricting HTTP access to WebLogic Server administrative consoles and sensitive endpoints using firewalls or reverse proxies that enforce strict IP whitelisting. Additionally, deploying a Web Application Firewall can help detect and block malformed requests characteristic of this vulnerability's exploitation pattern. Regular security assessments and penetration testing are recommended to identify similar misconfigurations in third-party dependencies across the organization's infrastructure.