CVE-2026-73878 in Helidon
Summary
by MITRE • 08/19/2026
Vulnerability in the Helidon product of Oracle Fusion Middleware (component: Imperative Web Server). The supported version that is affected is 3.2.18. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Helidon accessible data. CVSS 3.1 Base Score 7.5 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
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Analysis
by VulDB Data Team • 08/19/2026
The identified vulnerability resides within the Imperative Web Server component of Oracle Fusion Middleware Helidon, specifically affecting version 3.2.18. This security flaw represents a critical weakness in the application layer's handling of incoming HTTP requests, allowing for unauthorized access to sensitive data without requiring any form of authentication or user interaction. The nature of this vulnerability is consistent with improper input validation and authorization checks that are fundamental requirements for secure web server implementations as defined by industry standards such as CWE-287 Improper Authentication and CWE-352 Cross-Site Request Forgery if the flaw involves state-changing operations, though in this context it primarily points to a failure in enforcing access controls on sensitive endpoints. The vulnerability is easily exploitable over a network connection via HTTP, indicating that an attacker does not need complex social engineering or physical proximity to launch an attack, thereby significantly lowering the barrier for exploitation and increasing the risk profile of any system running this specific version of Helidon.
From a technical perspective, the flaw likely stems from a misconfiguration or code defect within the web server's routing logic where sensitive data endpoints are exposed without adequate security guards. When an unauthenticated attacker sends specifically crafted HTTP requests to these vulnerable endpoints, the server fails to verify the identity or privileges of the requester before serving the requested information. This behavior directly violates the principle of least privilege and secure by design methodologies mandated in frameworks like OWASP Top 10, particularly under categories related to broken access control. The absence of proper session management checks or API key validation allows malicious actors to bypass intended security boundaries, effectively treating protected resources as public ones. Such a defect transforms standard web server functionality into an attack vector that can be automated and scaled across the internet due to its simplicity and lack of prerequisites for exploitation.
The operational impact of this vulnerability is severe, characterized by high confidentiality impacts with a CVSS 3.1 Base Score of 7.5. Successful exploitation enables unauthorized access to critical data stored or processed by Helidon applications, potentially leading to complete exposure of all accessible information within the scope of the vulnerable component. This could include personally identifiable information, proprietary business logic, financial records, or other sensitive assets depending on the application's purpose. The integrity and availability impacts are listed as none in the provided vector, suggesting that while data theft is imminent, immediate system disruption or modification of server state may not be a direct consequence of this specific flaw alone; however, access to critical data often serves as a stepping stone for further attacks such as privilege escalation or lateral movement within an enterprise network. The ability to exfiltrate large volumes of sensitive information can result in significant regulatory penalties under laws like GDPR or HIPAA, alongside substantial reputational damage and loss of customer trust.
To mitigate this risk, immediate action is required to update the Helidon installation to a patched version where these access control mechanisms have been corrected by Oracle Fusion Middleware engineering teams. In environments where patching cannot be performed immediately due to operational constraints, network-level controls should be implemented to restrict HTTP traffic destined for vulnerable endpoints to trusted IP addresses only using firewall rules or Web Application Firewall policies that enforce strict authentication requirements before allowing requests to reach the application server. Additionally, security monitoring tools should be configured to detect anomalous patterns of unauthenticated access attempts to sensitive API paths, which may indicate active exploitation efforts. Regular vulnerability scanning and penetration testing focused on web application components are essential to identify similar misconfigurations in other parts of the infrastructure, ensuring a comprehensive defense against unauthorized data exposure threats aligned with MITRE ATT&CK techniques related to Collection via Local Network Capture or Application Layer Protocol if applicable to the specific data flow involved.